Five Vascular Warning Signs You Should Not Ignore

Leg pain when walking, a swollen calf, a foot wound that will not heal and troublesome varicose veins can all warrant a vascular assessment. Sudden severe chest, back or abdominal pain is different: it may be an emergency and must not wait for a clinic appointment.

To close his September vascular awareness series, Dr Andrew Choong describes five patterns worth recognising. These symptoms do not prove a particular diagnosis. Knowing what to do next helps you seek the right care at the right time.

For sudden severe chest, back or abdominal pain, collapse, stroke symptoms or a suddenly cold, painful or weak limb, call 995 in Singapore or your local emergency number elsewhere. Do not wait for a WhatsApp reply or travel to Singapore for a planned consultation.

1. Leg Pain When Walking That Improves With Rest

Repeated aching, cramping or tightness in the calf, thigh or buttock during walking may be claudication. This can occur when peripheral arterial disease (PAD) limits blood flow to working muscles. The discomfort often settles when you stop, then returns when you walk again.

Similar symptoms can come from joints, nerves or muscles. An assessment helps distinguish these causes and considers smoking, diabetes, cholesterol, blood pressure and kidney disease. Stable walking symptoms usually allow a planned review. New pain at rest or a sudden change in the foot’s temperature, colour, sensation or strength needs more urgent attention.

Treatment is not automatically an operation. Risk-factor management, prescribed medicines and structured exercise are important. Angioplasty or stenting may be considered in selected patients after reviewing the symptoms, anatomy, alternatives and risks.

2. A Painful, Swollen Calf, Especially on One Side

A new swollen, painful or tender calf can be a sign of deep vein thrombosis (DVT), a clot in a deep vein. Other conditions can cause swelling too, and DVT cannot be confirmed or excluded from appearance alone.

Seek urgent medical assessment for a suspected DVT, rather than waiting for a routine appointment. Tell the clinician when symptoms began and about recent travel, surgery, reduced mobility, illness or previous clots. Clinical assessment and appropriate testing establish the diagnosis and guide DVT treatment.

New breathlessness, chest pain, coughing blood or fainting may indicate a pulmonary embolism. Seek emergency care immediately; call 995 in Singapore for these potentially life-threatening symptoms.

3. A Foot or Toe Wound That Is Not Healing

A persistent wound may involve more than the skin. Reduced arterial blood flow can limit healing, while pressure, infection and reduced sensation may also contribute. This is particularly important in people with diabetes or kidney disease.

Do not wait for a small wound to become painful or black before seeking help. Diabetic foot and wound assessment considers the circulation alongside infection and pressure on the foot. Fever, spreading redness, blackened tissue, rapidly worsening pain or feeling unwell needs urgent medical attention.

A dressing alone will not resolve every underlying problem. Treatment may combine wound care, pressure relief, infection management and, when needed, restoration of blood flow. The plan depends on the individual findings; no procedure guarantees wound healing.

4. Varicose Veins With Symptoms or Skin Changes

Varicose veins are not always cosmetic. Heaviness, aching, swelling, skin darkening, eczema or an ulcer can indicate clinically important venous disease. Chronic venous insufficiency can affect the skin around the lower leg and ankle.

A vascular review can check for reflux, where faulty vein valves allow blood to flow backwards. Duplex ultrasound helps guide treatment when appropriate. Depending on the findings, options may include measures to manage symptoms or a procedure such as radiofrequency or laser ablation.

Bleeding from a varicose vein needs immediate medical attention. Heavy or uncontrolled bleeding is an emergency: call 995 in Singapore. Do not dismiss an episode simply because it has stopped.

5. Sudden Severe Chest, Back or Abdominal Pain

Sudden severe or unusual pain in these areas can have several serious causes. Occasionally it signals an aortic emergency, such as dissection or a complication of an aneurysm. Pain may be described as tearing, but it does not have to feel that way to be dangerous.

Call emergency services immediately. A routine vascular booking is not the correct first step. If you have a known aneurysm, tell the emergency team. The aortic disease guide explains surveillance and treatment planning for people who are stable; it does not replace emergency assessment.

What to Bring to a Planned Vascular Review

Bring previous scan images and reports, a medication list, details of earlier procedures and a short history of the symptoms. Note what brings them on and how they affect walking or daily activities.

For non-emergency advice or a second opinion, contact Andrew Choong Vascular Surgery at Mount Elizabeth Novena Specialist Centre, Singapore. See how to prepare for your visit and watch the five vascular warning signs video.

DVT Treatment Window: When Blood Thinners May Not Be Enough

Blood thinners are the main treatment for most deep vein thromboses (DVTs). In selected patients with an extensive clot affecting the large veins near the groin or pelvis, early assessment may also identify a role for clot removal or treatment of an underlying narrowing. The decision depends on symptoms, clot anatomy, timing and the risks of treatment.

In this video, Dr Andrew Choong, vascular and endovascular surgeon in Singapore, explains why a new DVT and persistent problems after an old DVT need different assessments.

Sudden breathlessness, chest pain, coughing blood or fainting may indicate a pulmonary embolism. Seek emergency care immediately; call 995 in Singapore for life-threatening symptoms. Do not wait for a routine appointment or an online reply.

What do blood thinners do for a DVT?

A deep vein thrombosis is a clot in a deep vein, commonly in the leg. Anticoagulants, often called blood thinners, reduce further clotting and help prevent the clot from growing or travelling to the lungs. They remain essential treatment for many patients.

They do not directly remove the clot or repair a scarred vein. The body gradually deals with the clot, and recovery varies. Some patients recover well with medication and follow-up; others have significant obstruction or persistent symptoms that warrant further assessment. Continue prescribed treatment and discuss any changes with your treating clinician.

When might early clot removal be considered?

The location matters. An iliofemoral DVT involves the iliac veins in the pelvis and/or the common femoral vein near the groin. Extensive clot in these veins can interfere substantially with blood draining from the leg, particularly when swelling and pain are severe.

Assessment considers:

• Where the clot is and how much of the vein is affected.

• When symptoms began and whether they are improving or worsening.

• The effect on walking, daily activity and the condition of the leg.

• Bleeding risk, recent surgery, other illnesses and the patient's preferences.

Selected patients with recent, symptomatic iliofemoral DVT may benefit from a discussion about early clot removal. For clot limited to veins farther down the thigh, behind the knee or in the calf, clot removal is generally not recommended. Severe, rapidly worsening swelling or pain with a marked change in leg colour needs emergency assessment.

What does the treatment window mean?

A fresh clot and longstanding scar tissue are different problems. Some clot-directed treatments are most relevant early, before the clot becomes more organised. This is why a newly diagnosed DVT with a very swollen, painful leg deserves prompt review of both the initial treatment and the clot's extent.

There is no single deadline that tells every patient whether a procedure will help. The technique, symptom duration, scan findings and overall health all matter. Seeking advice promptly preserves the opportunity to consider suitable options; it does not mean every patient needs an intervention.

What treatments may be discussed?

As Dr Choong explains, options in carefully selected cases include catheter-directed treatment, thrombectomy, venoplasty and venous stenting. Catheter-directed thrombolysis delivers clot-dissolving medicine into the clot. Thrombectomy uses a device to remove clot. If an important underlying vein narrowing is identified, a balloon or stent may sometimes be considered to improve drainage.

These approaches have different risks and evidence. Thrombolysis can cause major bleeding, and other procedures also have complications. Removing clot does not guarantee that post-thrombotic syndrome will be prevented, and anticoagulation usually remains part of care after an intervention. The DVT treatment guide explains how medication, selected procedures and follow-up fit together.

Why can symptoms persist months or years later?

A previous DVT can leave residual obstruction, vein scarring or damaged valves that allow backward flow, called reflux. The leg may remain swollen, heavy or painful. Skin around the ankle can darken, and some people develop venous ulcers. These problems may form part of post-thrombotic syndrome (PTS).

PTS can develop despite appropriate treatment. Persistent symptoms do not automatically mean that the original clot was treated incorrectly, that a new clot is present, or that a procedure is required. New or suddenly worsening symptoms need prompt assessment rather than being assumed to be the old problem.

A review asks whether there is residual blockage, pelvic vein narrowing, reflux or another explanation. Duplex ultrasound helps assess the veins; further imaging is selected when needed. Comparing previous scans can help distinguish longstanding changes from a new concern.

Preparing for a vascular review

Bring the date symptoms started, previous scan reports and images, hospital discharge information, and an up-to-date medication list. Describe how symptoms affect standing, walking, work and skin care. The aim is to understand the problem and discuss realistic options, including care without a procedure.

For ongoing symptoms after DVT or a discussion of an existing treatment plan, contact Andrew Choong Vascular Surgery at Mount Elizabeth Novena Specialist Centre, Singapore. A new suspected DVT needs urgent medical assessment. You can also watch Dr Choong's short explanation of the DVT treatment window.

DVT Warning: Red, hot, swollen painful leg

A new swollen, painful or unusually warm leg, especially on one side, needs urgent medical assessment. It may be a deep vein thrombosis, or DVT: a blood clot in a vein deep inside the leg. Not everyone has every symptom, and you should not wait for a complete checklist before seeking help.

In this video, I explain why this combination matters, which situations can increase the risk of a clot and how an ultrasound scan helps investigate it. The message is straightforward: do not dismiss a sudden change as ordinary tiredness or your usual leg swelling.

What symptoms can a DVT cause?

Possible symptoms include:

• Swelling: commonly affecting one leg more than the other.

• Pain or tenderness: often in the calf or thigh, without an obvious explanation.

• Warmth: an affected area that feels hotter than usual.

• A change in skin colour: including redness or darker colouring, which may be less obvious on some skin tones.

Other conditions, such as infection, injury or inflammation, can produce similar symptoms. Some people with DVT have few or no obvious signs. This is why appearance alone cannot confirm or exclude a clot. Our DVT information page explains the condition in more detail.

Why can a clot in the leg affect the lungs?

A DVT can interfere with blood drainage from the leg. If part of the clot breaks away, it can travel through the circulation and lodge in the blood vessels of the lungs. This is called a pulmonary embolism (PE), which can be life-threatening.

Sudden breathlessness, chest pain, coughing blood, fainting or collapse require emergency assessment. These symptoms can occur even without obvious leg symptoms. In Singapore, call 995 for a life-threatening emergency. Do not wait for a clinic appointment or an online reply.

Who has a higher risk of DVT?

In the video, I highlight cancer, some blood conditions, long-haul travel, periods of immobility and major orthopaedic surgery. These situations may increase the tendency for blood to clot or reduce its movement through the leg veins.

Previous DVT, pregnancy and the period after childbirth, and some hormone treatments are also relevant. Several risks can occur together. However, DVT can happen without an obvious trigger, so the absence of a recent flight or operation is not a reason to ignore symptoms.

Long journeys by car, bus or train can also involve prolonged sitting. The concern is not unique to flying; limited movement and a person’s underlying risk both matter.

How is a suspected DVT assessed?

A clinician will ask about the symptoms, examine the leg and review your risk factors. A venous duplex ultrasound is a common first-line imaging test. It examines the deep veins and helps identify a clot and its location.

Depending on the clinical assessment, blood tests or further imaging may also be needed. If symptoms persist or change after an initial assessment, follow the advice given about reassessment. A scan result needs to be interpreted alongside the full clinical picture.

What happens if a DVT is confirmed?

Treatment commonly involves anticoagulant medicines, often called blood thinners. They help stop the clot extending and reduce the risk of further clots while the body deals with the existing clot. The medicine and duration depend on factors such as the clot’s location, cause and bleeding risk.

Some patients need additional specialist treatment. Follow-up also considers ongoing swelling or discomfort and whether there are underlying factors to address. A new suspected clot needs urgent care, rather than treatment based only on information in a video.

What can you do before a long journey?

Move your legs regularly and take opportunities to walk when safe. Keeping normally hydrated is sensible, but drinking water alone should not be regarded as protection against a travel-related clot.

If you have had a clot, recent surgery, cancer or another significant risk factor, discuss travel precautions with your clinician beforehand. Compression stockings or preventive medicines are appropriate for selected people and should be individually advised.

Related DVT Guides

Read more about DVT treatment in Singapore, pulmonary embolism and vascular duplex ultrasound. These guides support the urgent-care advice above; do not delay assessment for new symptoms.

DVT assessment in Singapore

Seek urgent medical care for new one-sided painful swelling. For non-emergency questions about previous DVT or ongoing venous care, contact Andrew Choong Vascular Surgery at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563.

This article provides general education and does not replace an individual medical assessment.

What Is a Duplex Ultrasound? Vascular Surgeon Explains

Duplex ultrasound combines an image of a blood vessel with information about the blood flowing through it. Ultrasound provides the picture; Doppler assesses movement and flow. Together, they help us investigate problems affecting arteries and veins.

In this video, I explain why a duplex scan is frequently used for varicose veins, leg swelling, blocked arteries and possible blood clots. Understanding what the test measures can make a scan appointment less unfamiliar and help you understand the next steps in your care.

What does the ultrasound part show?

Ultrasound uses high-frequency sound waves. A probe sends these waves into the body and receives the echoes that return from tissues. The machine converts those echoes into an image.

For a vascular scan, this helps show the vessel and the structures around it. The person performing the scan can examine a particular area and take measurements relevant to the clinical question.

What does Doppler add?

Doppler uses changes in reflected sound waves to assess moving blood. It provides information about the direction and speed of flow, which can be displayed as colours or waveforms and sometimes heard as a sound.

This matters because a vessel’s appearance is only part of the story. I also need to understand whether blood is passing through effectively, whether flow is altered by narrowing, or whether it is moving backwards through a vein. Duplex brings the image and flow assessment together.

Which circulation problems can a duplex scan investigate?

• Varicose veins and venous reflux: identifying backward flow and mapping affected veins when assessing venous symptoms.

• Possible blood clots: examining the deep veins when deep vein thrombosis (DVT) is suspected.

• Narrowed or blocked arteries: assessing blood flow in people with symptoms that may relate to peripheral arterial disease.

• Treatment planning or follow-up: providing information that may guide a procedure or help assess circulation afterwards.

The scan is tailored to the reason for referral. An examination for venous reflux is not identical to an arterial scan or a scan for suspected DVT. Explaining your symptoms clearly helps ensure the assessment answers the relevant question.

What happens during the scan?

Usually, gel is applied to the skin and a handheld probe is moved over the area being examined. You may be asked to change position so the vessels can be assessed properly. The area needs to be accessible, so comfortable clothing can be helpful.

A standard external duplex scan is non-invasive and does not use ionising radiation. You may hear the machine’s blood-flow sounds during the examination. Let the sonographer know if an area is painful or if you have difficulty standing or changing position.

Preparation and appointment length depend on the vessels being examined. Follow the instructions supplied by the clinic rather than assuming every ultrasound appointment has the same requirements.

Does a scan result tell the whole story?

No single investigation replaces a clinical assessment. I interpret the findings alongside your symptoms, examination and medical history. Sometimes duplex provides the information needed; sometimes further tests or another form of imaging are appropriate.

Useful questions to ask include: What was the scan looking for? What did it show? Does the finding explain my symptoms? What should happen next? The aim is to connect the result to a clear care plan, rather than leave you with an unfamiliar technical term.

The vascular ultrasound guide explains different scan types, preparation, limitations and how results guide care.

Duplex ultrasound assessment in Singapore

As I explain in the video, our practice has its own vascular laboratory and a dedicated vascular sonographer who focuses on vascular scans. For advice about an assessment, contact Andrew Choong Vascular Surgery at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563.

New one-sided painful leg swelling needs urgent assessment; do not wait for a routine scan appointment. Sudden breathlessness, chest pain or collapse requires emergency care. Call 995 in Singapore for a life-threatening emergency.

This article provides general education and does not replace an individual medical assessment.

When Is Leg Swelling Not Just Water Retention? 2 of 2

Leg swelling that builds towards evening may be related to venous reflux, but new swelling in one leg needs prompt attention. A red, hot, painful calf can occur with deep vein thrombosis, and a clot does not always cause every one of those signs. The safest next step depends on the pattern and timing of symptoms.

This is the second part of the series. Part one explains the different causes of leg swelling.

What can the timing of swelling tell us?

With venous reflux, leaking valves make it harder for blood to return efficiently from the legs. Gravity and long periods with little movement can increase pressure in the veins. Some people notice more swelling after standing, sitting or travelling, and less after resting with their legs elevated.

That pattern can support a discussion about venous disease, but it cannot confirm the cause. In particular, swelling after a long flight should not automatically be dismissed as familiar reflux. A new one-sided change deserves assessment even if you have had varicose veins for years.

Does improvement with compression prove that the veins are responsible?

No. Feeling better in compression stockings can be useful information for your clinician, but it is not a diagnostic test. It does not rule out a blood clot or another explanation for swelling.

Tell your doctor what you have tried and how symptoms responded. If compression is being considered, the appropriate type and fit should be assessed, including whether arterial circulation or other health conditions make it unsuitable. New symptoms should be evaluated rather than managed simply by choosing tighter stockings.

When should one-sided leg swelling be checked?

New unexplained swelling affecting one leg should be checked promptly, especially if accompanied by calf pain, warmth, redness or a change in skin colour. These findings can occur with deep vein thrombosis, often called DVT, but can also have other causes.

A DVT is a clot in a deep vein. The classic description of a red, hot, swollen calf is a useful warning, not a checklist that must be complete. The absence of dramatic redness or severe pain does not safely exclude a clot. A clinician needs to assess the symptoms and relevant risk factors.

Which symptoms mean I should call for emergency help?

Call 995 in Singapore for sudden breathlessness, chest pain, coughing up blood or collapse, particularly when there is also leg pain or swelling. These can be signs of a pulmonary embolism, where a clot has travelled to the lungs, or another serious emergency.

Do not wait for a routine vein appointment if these symptoms occur. The priority is urgent hospital assessment. Leg swelling alone and leg swelling with breathing symptoms require different levels of urgency.

How does a duplex ultrasound help?

A duplex ultrasound provides information about the veins and the blood moving through them. For suspected venous reflux, the examination can assess valve function and identify the veins involved. This helps link the symptoms to an anatomical problem and supports treatment planning.

When a clot is suspected, the assessment follows an urgent diagnostic pathway. The clinician considers the history and examination and may arrange ultrasound and blood tests as appropriate. A scan requested for chronic reflux should not be assumed to replace a timely assessment for new DVT symptoms.

What should I tell the clinician?

Explain exactly when the swelling began, whether one or both legs are affected and how it differs from your usual pattern. Mention recent surgery, a hospital stay, reduced mobility, travel, cancer treatment or a previous clot. Include medicines, including hormone treatments, in your medication list.

If the swelling has been recurring over weeks or months, describe whether it improves overnight and whether there are visible veins or skin changes. This helps distinguish the questions that need to be answered rather than treating all swelling as the same condition.

What happens after the cause is identified?

Care depends on the diagnosis. Confirmed venous reflux, DVT and non-vascular causes of swelling need different approaches. An ultrasound result may lead to advice, further investigation or a discussion of suitable treatment; it does not mean everyone needs a vein procedure. Read more about varicose veins and venous conditions.

Our guide to varicose veins, DVT and leg swelling brings together the related conditions and assessment pathways.

Where can I arrange a non-emergency assessment?

For persistent or recurring symptoms, contact Dr Andrew Choong’s clinic at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563. Bring previous imaging and your medication list. For new one-sided swelling, seek prompt medical assessment; for chest or breathing symptoms, use emergency services.

This article provides general education and does not replace an individual medical assessment.

September is Vascular Disease Awareness Month | Signs & Symptoms

Leg pain when walking, persistent leg swelling and wounds that heal poorly can be warning signs of vascular disease. Some blood vessel conditions cause few or no symptoms until they become serious. Recognising a change in your circulation - and knowing when to seek help - is the message behind this video.

September’s vascular disease and peripheral arterial disease awareness campaigns are an opportunity to talk about arteries, veins, blood clots and the aorta. In the video above, I introduce a series of short explanations about vascular health, the symptoms people sometimes overlook, and when a proper assessment may be needed.

What is vascular disease?

Vascular disease affects the blood vessels that carry blood around the body. Arteries carry blood away from the heart; veins return it. The aorta is the body’s main artery.

Vascular conditions include peripheral arterial disease (PAD), varicose veins, deep vein thrombosis (DVT), aortic aneurysms and aortic dissection. These are different conditions, so their symptoms, risks and treatments are not interchangeable.

Heart health and arterial health are closely connected. PAD and coronary artery disease share risk factors such as smoking, diabetes, high blood pressure and high cholesterol. Looking after these risk factors matters beyond the heart itself.

Which symptoms should you look out for?

The topics introduced in this Short cover several changes worth paying attention to:

• Leg pain when walking. Aching or cramping brought on by walking and relieved by rest can be a sign of peripheral arterial disease, where narrowed or blocked arteries reduce blood flow to the legs. Repeated symptoms should not automatically be put down to age or fitness.

• Swelling, aching or heavy legs. These may occur with varicose veins or other venous problems. Persistent swelling, skin changes or ulcers deserve assessment; visible veins alone do not establish how serious a problem is.

• Foot or leg wounds that are slow to heal. Poor healing can have several causes, including impaired circulation. A foot wound in someone with diabetes needs prompt medical attention.

• New swelling in one leg. Especially when accompanied by pain, tenderness or warmth, this needs urgent medical assessment for a possible deep vein thrombosis. DVT is a clot in a deep vein, and not everyone develops all the typical symptoms.

These signs are reasons to seek advice, rather than a way to diagnose yourself. Muscle, joint and other medical problems can also cause leg symptoms.

Can vascular disease be silent?

Yes. Some vascular conditions develop without obvious warning signs. For example, an abdominal aortic aneurysm often causes no symptoms. An aneurysm is an abnormal widening of an artery; an aortic dissection involves a tear in the inner lining of the aorta.

This does not mean everyone needs a scan. Whether an examination, circulation test or imaging is appropriate depends on your symptoms, medical history and individual risk.

When should you seek urgent help?

Seek emergency care now for sudden severe abdominal or back pain, sudden breathlessness or chest pain, fainting, or a limb that suddenly becomes cold, painful or numb. These symptoms can signal serious problems and should not wait for a routine clinic appointment.

In Singapore, call 995 for a life-threatening emergency.

When is a vascular assessment appropriate?

Arrange a medical assessment for persistent or recurring leg pain when walking, unexplained swelling, skin changes or a wound that is not healing. Mention any diabetes, smoking history, high blood pressure or high cholesterol.

An assessment helps determine whether your symptoms relate to the arteries, veins or another cause, and whether further tests are needed. New one-sided swelling or rapidly worsening symptoms require more urgent attention.

Follow the September vascular health series

In this introductory video, I set out the topics for the month: walking-related leg pain, poor circulation, diabetic foot wounds, varicose veins, blood clots, aortic aneurysms and aortic dissections.

September also includes Aortic Dissection Awareness Day on 19 September and World Heart Day on 29 September. The next Short starts with a commonly missed warning sign of PAD: leg pain when walking.

Vascular care in Singapore

For non-emergency concerns about your circulation, contact Andrew Choong Vascular Surgery to enquire about an assessment with Dr Andrew Choong, Consultant Vascular and Endovascular Surgeon.

The clinic is at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563.

This article expands on the accompanying video for general education. It does not replace an individual medical assessment or personal medical advice.

What Is a Pulmonary Embolism? | Blood Clot Awareness Month | Video 4

A pulmonary embolism, or PE, happens when a blood clot blocks an artery in the lungs. It often begins as a clot in a deep vein in the leg or pelvis, called deep vein thrombosis, or DVT. Part of that clot can break away, travel through the right side of the heart and lodge in the pulmonary arteries.

In this fourth video of my Blood Clot Awareness Month series, I explain why recognising PE matters. It can be life-threatening, and the right response to possible symptoms is prompt medical assessment.

Why can a clot in the lungs be dangerous?

The pulmonary arteries carry blood from the heart to the lungs, where it picks up oxygen. A clot can obstruct that circulation, interfere with oxygen transfer and put strain on the right side of the heart.

The effect varies. Some people remain relatively stable, while others develop low oxygen levels, low blood pressure or collapse. The severity depends on the effect on the circulation and heart, alongside the person's overall health. A description of symptoms alone cannot establish how serious a PE is.

What symptoms need emergency attention?

Possible symptoms of pulmonary embolism include:

• Sudden or unexplained breathlessness.

• Chest pain, which may be worse when breathing in.

• Coughing up blood.

• A rapid heartbeat, marked light-headedness or fainting.

These symptoms may have other causes, but suspected PE needs emergency assessment. If you have symptoms suggesting PE, call 995 in Singapore. Do not wait for a routine clinic appointment or for symptoms to become severe.

Some people also have a painful, swollen or warm leg from an underlying DVT; others have no obvious leg symptoms. The absence of leg swelling does not rule out a pulmonary embolism.

How are DVT and pulmonary embolism connected?

DVT and PE are two forms of venous thromboembolism, often shortened to VTE. A deep-vein clot may stay in place, extend, or release material that travels to the lungs.

Risk can increase after surgery, during prolonged immobility, with active cancer, in pregnancy or after childbirth, and with certain hormone medicines. A previous blood clot also matters. Sometimes no clear trigger is identified. Knowing the circumstances helps guide treatment and decisions about preventing another clot.

I explain the leg-vein condition in more detail on my deep vein thrombosis page.

For treatment of related leg-vein clots, read the DVT treatment guide.

How is pulmonary embolism diagnosed?

Assessment combines the symptoms, risk factors, examination and appropriate investigations. Depending on the clinical situation, these may include blood tests and imaging. CT pulmonary angiography is commonly used to look for clots in the pulmonary arteries; alternative imaging may be chosen when it is more appropriate.

Tests may also assess the effect on the heart and oxygen levels. This information helps the treating team decide the urgency, location and type of care needed. Not everyone requires the same tests or treatment pathway.

Does every pulmonary embolism need clot removal?

No. Anticoagulant medicines are the main treatment for many people with PE. Often called blood thinners, they reduce further clotting while the body's own processes gradually deal with the clot. They do not physically extract it.

In the video, I describe aspiration thrombectomy: a catheter-based procedure that can remove clot from the pulmonary arteries. This is an option for selected patients, particularly when PE is causing serious circulatory problems or when the balance of risks favours an intervention.

Other advanced treatments include clot-dissolving medication or surgical removal in particular circumstances. These approaches carry risks and require specialist assessment. A procedure is not automatically better than anticoagulation, and recovery time cannot be promised in advance.

What happens after the immediate treatment?

Follow-up matters. The team reviews medication, bleeding risk, the likely cause of the clot and how long treatment should continue. Persistent breathlessness or reduced exercise tolerance after PE should be discussed rather than assumed to be part of normal recovery.

The pulmonary embolism guide brings together warning signs, treatment and follow-up after a lung blood clot.

For a non-emergency discussion about DVT, clot risk or vascular follow-up in Singapore, you can contact my clinic at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563. New symptoms suggesting PE require emergency assessment first.

This article provides general education and does not replace an individual medical assessment.

What Is a DVT? Deep Vein Thrombosis Explained

Deep vein thrombosis, or DVT, is a blood clot in a deep vein. It most often affects the leg or pelvis, although it can also develop in an arm. Deep veins carry blood back towards the heart, so a clot can obstruct that return flow.

In the third instalment of my Blood Clot Awareness Month series, I explain why DVT deserves attention: it can cause immediate symptoms, sometimes lead to a pulmonary embolism, and leave longer-term problems in the affected leg. Recognising a possible clot is the first step towards getting it assessed.

What does a DVT feel or look like?

Possible signs include new swelling, pain or tenderness, warmth, and a change in skin colour, usually affecting one leg. The discomfort may involve the calf or thigh. An arm DVT can produce similar symptoms in the arm.

These signs do not prove that a clot is present. Muscle injuries, infections and other conditions can look similar, and some DVTs cause few or no obvious symptoms. Comparing one leg with the other can reveal a change, but a home examination cannot confirm or exclude DVT.

New, unexplained one-sided swelling or pain warrants urgent medical assessment. Do not wait for symptoms to become severe before seeking advice.

Why can a leg clot affect the lungs?

Part of a DVT can break off and travel through the bloodstream to the pulmonary arteries in the lungs. This is called a pulmonary embolism, or PE. It can interfere with oxygen exchange and strain the heart.

Sudden breathlessness, chest pain, coughing up blood or fainting need emergency assessment. For these possible pulmonary embolism symptoms, call 995 in Singapore; do not wait for symptoms to worsen. A routine vascular appointment is not the appropriate first step when PE is suspected.

DVT and PE are related conditions collectively called venous thromboembolism, or VTE. Not every DVT causes PE, but the possibility is one reason early diagnosis and treatment matter.

Can DVT threaten the leg itself?

Rarely, a very extensive DVT can severely obstruct the veins draining the leg. The leg may become dramatically swollen, very painful and discoloured. This severe condition, known as phlegmasia, can threaten the limb and requires emergency specialist care.

This is different from the more usual presentation of DVT, but it illustrates why a rapidly worsening, painful swollen leg should not be managed by waiting at home. Emergency assessment is particularly important if the limb becomes blue, cold or numb.

What is post-thrombotic syndrome?

After a DVT, residual obstruction or damage to the vein valves can make it harder for blood to return efficiently. Some people develop post-thrombotic syndrome, with persistent swelling, aching, heaviness or skin changes. In more severe cases, a venous ulcer can develop.

These problems can affect daily life even after the immediate clot has been treated. They do not happen to everyone. Follow-up allows ongoing symptoms to be assessed and a suitable management plan to be discussed.

Who is more likely to develop DVT?

Risk factors include recent surgery or hospitalisation, reduced mobility, a previous clot, active cancer, pregnancy and the period after childbirth. Certain hormone medicines and inherited clotting tendencies can also increase risk.

Long journeys can contribute through prolonged sitting, particularly when other risk factors are present. Sometimes a DVT develops without an obvious trigger. The clinical history helps determine both the likely cause and how best to reduce future risk.

How is DVT assessed and treated?

A clinician considers the symptoms, examination and risk factors. An ultrasound scan is commonly used to look for a clot in the deep veins; blood tests may form part of the assessment in selected circumstances.

Anticoagulant medicines are the main treatment for most DVTs. They help prevent the clot growing and reduce the chance of further clots while the body's natural processes work on the existing clot. Treatment duration depends on the individual situation.

Selected patients with extensive, severely symptomatic clots may be considered for catheter-based treatment. This is not necessary for every DVT. Decisions balance potential benefit against bleeding and procedural risks.

For more detail, read the guides to DVT treatment, venous duplex ultrasound and pulmonary embolism.

You can read more about DVT assessment and treatment or contact my Singapore clinic at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563 for non-emergency advice and follow-up.

This article provides general education and does not replace an individual medical assessment.

Why Do Blood Clots Form? DVT & PE Risk Explained

Why does a blood clot develop inside a vein when there has been no visible cut or injury? In this second video of my Blood Clot Awareness Month series, I explain three processes that help answer that question: slow blood flow, a greater tendency to clot, and injury to the vessel lining.

Together, these are known as Virchow's triad. One or more can contribute to deep vein thrombosis, or DVT. Understanding them helps explain why clot risk often changes around an operation, illness, pregnancy or a period of reduced mobility.

What happens when blood flow slows?

Movement helps blood return from the legs towards the heart. When the calf muscles contract, they support that return flow through the veins. Long periods without normal movement can allow blood to pool and increase the opportunity for a clot to form.

This can happen during bed rest, recovery from major surgery or a long journey. The level of risk varies: a person with a previous DVT, active cancer or several other risk factors may need a different prevention plan from someone without those factors.

Prolonged sitting is therefore part of the explanation, rather than a complete explanation on its own. An otherwise ordinary journey may become more relevant when it follows an operation or takes place during a period of illness.

When is blood more likely to clot?

Some conditions shift the body's clotting balance towards clot formation. Active cancer, pregnancy and the period after childbirth are examples. Certain hormone medicines and inherited clotting disorders can also contribute.

Previous DVT or pulmonary embolism is particularly relevant to a risk assessment. Family history can provide useful context, although it does not automatically mean someone has an inherited disorder or needs a blood test for one.

If you take a prescribed medicine that may affect clot risk, discuss it with your clinician. Stopping treatment without advice can create other problems; prevention decisions need to account for both the reason for the medicine and your individual circumstances.

How does injury to a vessel lining contribute?

The inside surface of a blood vessel normally helps blood flow smoothly. Surgery, trauma and inflammation can disturb that lining and activate the clotting response.

After an operation, several parts of the triad can overlap: there may be tissue or vessel injury, less movement than usual and a temporary change in clotting activity. That is why clot prevention is considered as part of surgical care, with measures chosen for the procedure and the patient.

A clot can also develop without a clearly identifiable trigger. The absence of recent travel or surgery does not rule out DVT.

What can help reduce the risk?

Prevention should match the situation. Useful discussions include when it is safe to mobilise after surgery, how to avoid prolonged immobility during travel, and whether a particular illness or previous clot calls for additional measures.

For some people, clinicians recommend anticoagulant medication or suitable compression as part of a prevention plan. These are not measures that everyone should start independently. Bleeding risk and other medical conditions affect what is appropriate.

Keeping normally hydrated is sensible general care, but drinking water is not a proven substitute for movement or an individual clot-prevention plan. If you have a previous clot or several risk factors, seek advice before a long journey or planned operation.

Which symptoms should not be ignored?

DVT may cause new swelling, pain, warmth or a colour change in one leg. These symptoms need urgent assessment because an examination alone cannot reliably establish the cause.

A clot can travel from a deep vein to the lungs and cause pulmonary embolism. Sudden breathlessness, chest pain, coughing up blood or fainting require emergency assessment. For these possible pulmonary embolism symptoms, call 995 in Singapore; do not wait for a routine appointment.

You can read more about deep vein thrombosis and its assessment. For a planned discussion of vascular symptoms or clot risk, contact my Singapore clinic at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563.

This article provides general education and does not replace an individual medical assessment.

What is a Blood Clot? | Singapore Vascular Surgeon

A blood clot is a mass formed when blood changes from a flowing liquid into a more solid structure. Clotting is normally protective: after an injury, it helps stop bleeding. The problem arises when a clot forms inside a blood vessel where it is not needed and obstructs the circulation.

In the first video of my Blood Clot Awareness Month series, I introduce this distinction. A clot is not simply “good” or “bad” in isolation. Its location, cause and effect on blood flow determine what it means for your health.

How does normal clotting protect us?

When a blood vessel is injured, platelets gather at the damaged area and help form a plug. Clotting proteins create a mesh of fibrin that supports it. Together, these processes help seal the injury while healing takes place.

The body also has mechanisms that limit clotting and break down clots when they are no longer needed. Health depends on keeping that balance: too little clotting can cause bleeding, while inappropriate clotting can block a vessel.

What is the difference between a clot in a vein and an artery?

Arteries carry blood away from the heart to supply the body. Veins return blood towards the heart. A clot can develop in either system, but the consequences and treatments differ.

A vein clot can obstruct blood returning from a limb and may travel to the lungs. An artery clot can interrupt the oxygen-rich blood reaching an organ or limb. The word “clot” therefore covers several conditions; it does not identify one diagnosis or one treatment.

My overview of vascular surgery explains how arterial and venous conditions fit within vascular care.

What are DVT, PE and VTE?

Deep vein thrombosis (DVT) is a clot in a deep vein, most often in the leg or pelvis. It may cause new one-sided swelling, pain, warmth or a change in skin colour, although some people have few obvious symptoms.

Pulmonary embolism (PE) occurs when a clot, commonly from a DVT, travels to and blocks an artery in the lungs. It can affect breathing and place strain on the heart.

Venous thromboembolism (VTE) is the collective term for DVT and PE. Understanding these terms helps make sense of medical discussions, but symptoms still need an assessment rather than a diagnosis based on an online description.

What is acute limb ischaemia?

A sudden blockage of an artery supplying a limb can cause acute limb ischaemia. This means the tissues are not receiving enough blood and oxygen. It is a vascular emergency.

A suddenly painful, cold, pale or numb foot or leg, particularly with weakness, requires immediate emergency assessment. Do not wait to see whether walking, massage or rest resolves it. It is different from the recurring walking discomfort described in peripheral arterial disease, although both involve the arterial circulation.

When should I seek help for a possible clot?

New, unexplained swelling or pain in one leg warrants urgent medical assessment for possible DVT and other causes. Sudden breathlessness, chest pain, coughing up blood or fainting could indicate PE and require emergency assessment.

For possible pulmonary embolism symptoms or a suddenly cold, painful, numb or weak limb, call 995 in Singapore. Early assessment allows the treating team to identify the problem and start appropriate care.

How are blood clots treated?

Treatment depends on where the clot is, how it is affecting the circulation and the person's overall health. Anticoagulants are commonly used for DVT and PE to reduce further clotting while the body works on the existing clot.

Some situations require clot-dissolving treatment, catheter-based removal or surgery. These are selected according to urgency, expected benefit and risk; they are not interchangeable treatments for every clot.

The guides to DVT treatment and pulmonary embolism explain these care pathways in more detail.

For a non-emergency discussion about DVT, previous clots or vascular symptoms, contact my clinic at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563. Dr Andrew Choong's clinic can support assessment and follow-up, while acute emergency symptoms require immediate hospital care.

This article provides general education and does not replace an individual medical assessment.

Blood Clot Removal for DVT | Modern Treatment Explained

Treatment for deep vein thrombosis, or DVT, can now include catheter-based techniques that remove clot from a vein. In this video, I explain how vascular treatment has developed, from anticoagulant medicines to clot-dissolving therapies and mechanical clot removal.

These developments add options for selected patients. They do not mean every DVT needs a procedure. The central question is whether removing the clot is likely to offer enough benefit for that person to justify the risks.

Why are anticoagulants still central to DVT treatment?

Anticoagulants, often called blood thinners, reduce the blood's ability to form further clot. They help prevent an existing DVT from growing and lower the risk of additional clots while the body's own processes gradually deal with it.

For most people with DVT, anticoagulation remains the main treatment. The medication, duration and follow-up plan depend on factors such as the clot's location, its likely cause, previous clotting events and bleeding risk.

A procedure does not automatically replace anticoagulation. Many patients still need medication afterwards, together with monitoring and advice about future clot risk.

What is catheter-based blood clot removal?

A catheter is a thin tube introduced into a blood vessel through a small access point. Guided by imaging, it can be positioned near or within a clot. The technique used depends on the clot, the anatomy and the clinical circumstances.

Catheter-directed thrombolysis delivers clot-dissolving medicine to the affected area. Mechanical thrombectomy uses a device to remove clot; aspiration thrombectomy uses suction. Sometimes approaches are combined, and a separate narrowing in the vein may need assessment.

These procedures differ from simply taking anticoagulant medication. They aim to clear clot more directly, but each approach has limitations and potential complications.

Who might benefit from a procedure for DVT?

Specialist assessment may consider an intervention for selected patients with a recent, extensive and severely symptomatic clot, particularly involving the major veins in the upper thigh and pelvis. Rarely, a DVT severely compromises drainage from the limb and becomes a limb-threatening emergency.

Important considerations include:

• Where the clot is and how long symptoms have been present.

• The severity of swelling, pain and any threat to the limb.

• Bleeding risk, other medical conditions and functional needs.

• The likely benefit of a procedure compared with medication alone.

A smaller or less symptomatic clot may be best managed without an intervention. Having access to modern technology is useful when it supports the right decision for the patient.

Can clot removal prevent long-term leg problems?

Some people develop persistent swelling, aching, skin changes or ulcers after a DVT. This is called post-thrombotic syndrome and can reflect lasting vein obstruction or damage to the valves.

Removing clot may improve symptoms in appropriately selected patients, but it cannot guarantee that the leg will return completely to normal or that post-thrombotic syndrome will be prevented. Results vary with the clot, the vein and the individual.

Follow-up remains important whether treatment involves medication alone or a procedure. Persistent symptoms deserve review and a management plan suited to their cause.

What about clot removal from the lungs?

The video also describes aspiration treatment for pulmonary embolism, where a clot blocks arteries in the lungs. Catheter-based removal is an option in selected serious cases, within an urgent specialist treatment pathway.

Many pulmonary embolisms are treated with anticoagulation. More advanced treatment is considered according to the effects on the circulation and heart, the person's condition and the risks of treatment. It is not a routine extension of every DVT procedure.

What should I discuss before treatment?

Ask what the proposed treatment aims to achieve, what medication alone is expected to do, and which risks apply to you. Depending on the procedure, risks can include bleeding, vessel injury, problems related to contrast and the need for further treatment. Recovery and follow-up requirements should also be clear.

The DVT treatment guide brings together medicine, selected clot-removal procedures, venous stenting and follow-up.

New one-sided leg swelling or pain needs urgent assessment. Sudden breathlessness, chest pain or fainting can indicate pulmonary embolism and requires emergency care. Call 995 in Singapore; do not wait for a routine appointment.

For non-emergency advice, read more about DVT treatment or contact my clinic at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563. I can discuss which options fit your diagnosis and circumstances.

This article provides general education and does not replace an individual medical assessment.

World Thrombosis Day: How DVT and Pulmonary Embolism Can Be Fatal

A blood clot in a deep leg vein can become life-threatening if part of it travels to the lungs. That is the connection between deep vein thrombosis (DVT) and pulmonary embolism (PE), and it is the central message of my World Thrombosis Day video.

I am Dr Andrew Choong, a vascular surgeon in Singapore. On 13 October, World Thrombosis Day is an opportunity to explain what blood clots are, who may be at risk and which symptoms should prompt action. Recognising a possible clot early can make an important difference.

What is the difference between DVT, PE and VTE?

Deep vein thrombosis means a blood clot has formed within a deep vein, commonly in the leg. It can obstruct the return of blood towards the heart and cause swelling or discomfort. Some clots produce few obvious symptoms.

A pulmonary embolism happens when clot material travels through the circulation and blocks an artery in the lungs. The consequences range from breathlessness to a dangerous strain on the heart and sudden collapse. DVT and PE together are called venous thromboembolism, or VTE.

Thrombosis also occurs in arteries. The widely used World Thrombosis Day statistic that around one in four deaths worldwide involves a condition caused by thrombosis includes conditions such as heart attack and stroke; it does not mean that one in four people dies from a leg DVT.

Why can a blood clot develop?

Clot formation becomes more likely when blood flow slows, the vessel lining is affected or the blood has an increased tendency to clot. These factors can overlap. In my video, I highlight surgery, prolonged immobility and long journeys as situations in which people should be aware of their individual risk.

Hospital admission is especially important. Up to 60% of VTE cases are associated with a hospital stay, occurring during admission or within 90 days afterwards. That is why prevention planning may continue beyond the day a patient leaves hospital.

Your risk depends on the whole picture, including previous clots, current illness and treatment. A long flight does not affect everyone equally, and prevention should reflect your circumstances.

Which symptoms should I recognise?

A possible DVT needs prompt medical assessment, particularly when a change affects one leg. Warning signs may include:

• New swelling of the calf or whole leg.

• Pain or tenderness without a clear explanation.

• Warmth or a change in skin colour.

Sudden unexplained breathlessness, chest pain, fainting or collapse can indicate PE or another serious emergency. A racing heartbeat may accompany these symptoms. In Singapore, call 995 for an emergency ambulance when severe symptoms develop. Do not wait for a routine clinic appointment.

Symptoms alone cannot confirm or exclude a clot. Other conditions can look similar, and the absence of dramatic swelling does not make every situation safe.

How are DVT and pulmonary embolism treated?

Assessment starts with the symptoms and risk factors. Depending on the findings, clinicians use blood tests and appropriate imaging, such as ultrasound for suspected leg DVT. Testing is selected for the clinical situation.

Anticoagulant medication is central to treatment for many patients. It reduces the risk of clot extension and further clot formation while the body deals with the existing clot. The choice and duration require an individual assessment, including bleeding risk.

In selected cases, specialists may consider catheter-based treatment to remove or dissolve clot. My video describes the role of vascular surgeons in restoring blood flow, but a clot-removal procedure is not necessary or suitable for every DVT. The location, severity, timing and patient’s overall condition all matter.

What can I do after watching this video?

Know the warning signs, follow your hospital team’s prevention instructions and discuss personal clot risk before major surgery or prolonged immobility. If you develop new symptoms after discharge, mention your recent admission when seeking help.

For a non-emergency discussion about DVT and venous health, you can contact Andrew Choong Vascular Surgery. Current clinic location: Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563.

Vascular Surgery in 60 Seconds: Aorta, Arteries and Veins Explained

A vascular surgeon is a specialist in the blood vessels that carry blood around the body. In my 60-second video, I describe us as circulation doctors: we assess and treat problems affecting arteries and veins, using a range of medical, minimally invasive and open surgical approaches.

I am Dr Andrew Choong, a vascular surgeon in Singapore. Understanding the scope of vascular surgery can help you recognise why symptoms as different as walking pain, swollen legs and a wound that will not heal may need a circulation assessment.

What is the difference between an artery and a vein?

Arteries carry blood away from the heart towards the tissues. Veins return blood towards the heart. They are parts of the same circulation, but the conditions affecting them - and the tests and treatments they need - can be very different.

An artery narrowed by disease may not deliver enough blood to a muscle or wound. A vein with faulty valves may allow blood to pool in the leg. A blood clot can cause another kind of obstruction. The first job is to identify which problem is present.

Which conditions does a vascular surgeon treat?

Vascular surgery covers a broad range of circulation problems. The examples in my video include:

• Aortic disease: aneurysms and dissections affecting the body’s main artery.

• Leg artery disease: narrowed or blocked arteries that may cause walking pain, rest pain or poor wound healing.

• Venous disease: varicose veins and deep vein thrombosis.

• Carotid artery disease: selected artery problems in the neck relevant to stroke prevention.

• Dialysis access: creating and maintaining suitable access to the circulation for haemodialysis.

Wound care and limb preservation are also important parts of vascular practice. When poor blood flow contributes to a foot or leg wound, addressing the circulation may be one part of a wider treatment plan.

Is vascular surgery the same as cardiology?

The specialties are related, but their focus differs. Cardiologists primarily assess and treat the heart. Vascular surgeons mainly manage blood vessels outside the heart and brain, including the arteries in the neck and vessels throughout the body.

Some techniques overlap. Balloons, wires and stents can be used in both heart and peripheral vascular procedures. The presence of a stent does not, by itself, tell you which specialty or condition is involved.

Complex aortic and other vascular conditions may also involve several specialties working together. The appropriate team depends on the part of the circulation affected and the treatment required.

Does seeing a vascular surgeon mean I need an operation?

No. An assessment may lead to advice, medication, monitoring or further tests. For example, management of peripheral arterial disease can include cardiovascular risk reduction and structured exercise, with a procedure considered when clinically indicated.

For some patients, endovascular treatment offers a way to work inside a blood vessel through a small access site. Depending on the problem, this may involve a balloon, stent or another device. Other patients are better served by open surgery, such as a bypass or repair.

The decision starts with the diagnosis, symptoms, scan findings and goals of treatment. A procedure should have a clear purpose that the patient understands.

When should I seek a circulation assessment?

Persistent leg pain when walking, troublesome varicose veins, unexplained swelling or a wound that is not healing deserve medical attention. These symptoms have several possible causes, so an examination is more useful than assuming that every leg problem is vascular.

Some changes are emergencies. A suddenly cold, pale, painful or weak limb, sudden severe chest or back pain, or sudden breathlessness with collapse needs immediate emergency assessment. In Singapore, call 995 for severe emergency symptoms.

Where can I discuss vascular symptoms in Singapore?

You can contact Andrew Choong Vascular Surgery for a non-emergency consultation to discuss your symptoms, relevant scans and treatment options. My aim is to explain the circulation problem and the reasons for any proposed next step.

Current clinic location: Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563.