Aortic Aneurysm vs Aortic Dissection: What’s the Difference?

An aortic aneurysm is an abnormal enlargement of the aorta. An aortic dissection is a tear in its inner lining that allows blood to separate the layers of the artery wall. They can occur separately or together. Both can be serious, but the diagnosis, urgency and treatment are different.

In this video, Dr Andrew Choong, vascular and endovascular surgeon in Singapore, explains why these terms matter when understanding an aortic diagnosis.

What is an aortic aneurysm?

The aorta is the body’s largest artery, carrying blood from the heart through the chest and abdomen. An aneurysm develops when part of it becomes abnormally enlarged, rather like a balloon.

An aneurysm in the abdomen is called an abdominal aortic aneurysm, or AAA. One in the chest is a thoracic aortic aneurysm. Some cause no symptoms and are found during imaging for another reason. The concern is that the weakened section may enlarge and eventually rupture. An aneurysm diagnosis does not, however, mean it has already burst.

What is an aortic dissection?

With a dissection, a tear in the inner lining allows blood to track between the layers of the aortic wall. This creates a second channel called a false lumen, alongside the original blood channel.

A dissection can disrupt blood flow to important organs and can lead to rupture. It requires a different assessment from simply measuring an enlarged aorta. Our aortic disease guide explains these conditions in more detail.

Can you have one without the other?

Yes. As the video explains, you can have an aneurysm without a dissection, and a dissection without an aneurysm. They can also coexist. A previously dissected aorta may enlarge over time, so follow-up remains important even after the initial event has been treated.

Rupture is another distinct term: it means blood escapes through the wall of the aorta. Neither “aneurysm” nor “dissection” automatically means rupture has occurred.

Why does the difference change treatment?

Aneurysm care

A stable aneurysm may be monitored with scans and treatment of relevant risk factors. Whether repair is appropriate depends on its location, size, growth, symptoms and the person’s overall health. Not every aneurysm needs an operation immediately.

Depending on the anatomy, options may include endovascular aneurysm repair (EVAR) for suitable abdominal aneurysms, thoracic endovascular aortic repair (TEVAR) for suitable disease in the chest, or open aortic surgery. These approaches are not interchangeable for every patient.

Dissection care

Suspected acute dissection needs urgent hospital assessment. A dissection involving the ascending aorta near the heart usually requires emergency surgery. Some uncomplicated dissections confined to the descending aorta are initially managed in hospital with medication and close monitoring; complications may require intervention. The scan findings and clinical situation determine the plan.

When should you seek emergency help?

Call 995 in Singapore for sudden severe chest, back or abdominal pain, particularly with collapse, breathlessness or sudden weakness. These symptoms may signal an aortic emergency or another life-threatening condition. Do not wait for a routine clinic appointment. Read more about aortic emergency awareness.

Who should discuss assessment or screening?

If you have a known aneurysm, previous dissection, a relevant family history or an abnormal scan, discuss an individual assessment and follow-up plan. Screening is based on risk; the video’s advice to seek assessment should not be taken to mean that everyone needs a scan.

For non-emergency concerns, contact Andrew Choong Vascular Surgery at Mount Elizabeth Novena Specialist Centre, Singapore. Bring any previous scan reports so the discussion can focus on your diagnosis and options. If you already have an aortic diagnosis, see how to arrange an aortic second opinion and prepare your existing scans. You can also watch the short explanation in the video library.

Aortic Dissection Warning Signs: Think Aorta! Get a Contrast CT

Sudden severe chest, back or abdominal pain needs urgent emergency assessment. If you or someone with you has these symptoms, particularly with collapse, breathlessness or new weakness, do not wait at home or book a routine clinic visit. In Singapore, call 995 for emergency ambulance help.

In this video, ahead of Aortic Dissection Awareness Day, I explain why aortic dissection must remain a possibility when symptoms are sudden and serious. The message “Think Aorta” is a reminder to recognise the emergency and consider the diagnosis promptly.

What is an aortic dissection?

The aorta is the main artery carrying blood from the heart to the body. An aortic dissection occurs when a tear in its inner lining allows blood to enter and separate layers within the wall.

This can disrupt blood flow to important organs or limbs and can lead to other life-threatening complications. It is different from an aneurysm, which describes abnormal enlargement of an artery, although the two conditions can occur together. My aortic disease guide explains these differences in more detail.

What are the warning signs?

The classical symptom is pain that starts suddenly and is severe from the outset, often in the chest, back or abdomen. Some patients describe it as tearing or ripping; others describe the worst pain they have experienced.

However, you should not wait for a particular description of pain before seeking help. Aortic dissection does not always present in a textbook way, and a person may not use the words “tearing” or “ripping” at all.

Concerning features can include:

• Sudden severe chest, back or abdominal pain.

• Fainting, collapse or rapidly worsening illness.

• New weakness, difficulty speaking or other stroke-like symptoms.

• A sudden problem with circulation to a limb, such as pain, coldness or weakness.

These symptoms can also indicate other emergencies. The need for urgent care remains the same even when the exact cause is uncertain.

Why can aortic dissection be mistaken for something else?

In my video, I describe dissection as a clinical mimicker. Depending on the part of the aorta and its branches affected, it can resemble a heart attack, stroke, abdominal illness or limb circulation problem.

That is why the whole clinical picture matters. How suddenly did the symptoms start? Where is the pain? Are there changes in consciousness, movement or circulation? The emergency team brings these findings together rather than relying on a single symptom.

What does “get a contrast CT” mean?

When clinicians suspect an acute aortic problem, CT angiography is commonly used because it can rapidly show the aorta, the extent of a dissection and involvement of its branches. Contrast helps define the blood-filled channels and surrounding anatomy.

The phrase in my video is an awareness message about timely diagnosis. It is not advice for everyone with ordinary back pain to arrange a CT independently. The emergency team decides which imaging is appropriate, taking account of the clinical situation, stability, contrast history and other relevant factors. Alternative imaging may be needed in selected circumstances.

What should I tell the emergency team?

Describe when the symptoms began and whether they were sudden and severe. Mention known aortic disease, previous aortic procedures or a relevant family history if you know about them. Share your medication list and allergies when possible, without delaying the emergency call.

You do not need to prove that you have a dissection before asking for help. The priority is prompt assessment of a potentially serious event. Do not drive yourself if you are acutely unwell, and do not wait for a clinic message to be answered.

How is ongoing aortic care arranged in Singapore?

After an emergency has been assessed and treated, ongoing care may include blood-pressure management, specialist review and surveillance imaging. The plan depends on which part of the aorta is affected and the treatment already received.

For a non-emergency review of known aortic disease or a scan, contact Andrew Choong Vascular Surgery at Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563. You can also explore my aortic awareness information.

Awareness is useful when it leads to timely action: sudden, severe or otherwise concerning symptoms belong in an emergency assessment, not a period of observation at home.

Aortic Dissection Awareness Day: Recognising a Vascular Emergency

Aortic dissection is a medical emergency in which blood enters a tear in the inner lining of the aorta and separates layers of its wall. Because the aorta supplies blood to the whole body, the consequences can develop quickly and involve more than the chest.

In this Aortic Dissection Awareness Day talk, published on 19 September 2024, I explain why recognising the possibility matters. I am Dr Andrew Choong, a vascular surgeon in Singapore. My message is to think about the aorta when symptoms and circumstances suggest a serious aortic problem, so that appropriate assessment is not delayed.

What happens during an aortic dissection?

The aorta is the main artery leaving the heart. It travels through the chest and abdomen, with branches supplying the brain, arms, abdominal organs and legs. Its wall is made of layers.

When blood tracks between those layers, it can disrupt blood flow to important branches. A dissection can also be associated with rupture or other life-threatening complications. The location and extent determine which organs are at risk and what treatment is needed.

A dissection is different from an aneurysm. An aneurysm is an abnormal enlargement of an artery; dissection refers to separation within the wall. Both fall within aortic disease, but they are not interchangeable terms.

Which symptoms should raise concern?

Sudden, severe chest or back pain is an important warning pattern, especially when the pain is at its worst from the beginning. Some people describe tearing pain, but that description is not essential. Abdominal pain or other symptoms may occur.

Depending on the branches involved, there may also be fainting, stroke-like symptoms, severe breathlessness or a painful, cold or weak limb. In the talk, I describe aortic dissection as a condition that can mimic other emergencies.

If sudden severe symptoms occur, call 995 in Singapore for emergency assessment. Do not wait for a clinic appointment or try to decide from an online checklist whether the pain is definitely a dissection. Other causes of sudden severe pain may also require urgent care.

How do doctors diagnose aortic dissection?

The emergency team considers the symptoms, examination and medical history, including known aortic disease or relevant inherited conditions. High blood pressure is an important risk factor, although its presence alone does not diagnose a dissection.

CT angiography is commonly used when acute aortic disease is suspected because it can show the aorta and its branches quickly and in detail. In particular circumstances, other imaging such as transoesophageal echocardiography or MRI may be appropriate.

The “think aorta” message is a prompt for timely clinical judgement and suitable imaging. It does not mean that every episode of back pain needs a CT scan. The choice of test depends on the level of concern and the patient’s condition.

How is an aortic dissection treated?

Treatment depends on which part of the aorta is involved and whether complications are present. A dissection involving the ascending aorta, called type A, generally requires urgent surgical assessment and repair.

A type B dissection does not involve the ascending aorta. If it is uncomplicated, treatment often begins with careful medical management, including control of blood pressure and heart rate, followed by surveillance. Complications such as threatened organ blood flow or rupture may require intervention.

For selected patients, an endovascular stent graft can be placed through the blood vessels to cover the entry tear and redirect blood flow. Other situations require open surgery. The safest approach is determined by the anatomy, urgency and specialist assessment.

Separate guides explain TEVAR for selected type B dissection and open, hybrid and endovascular aortic arch repair.

Why is follow-up important after treatment?

Recovery from the immediate event is one stage of care. The remaining aorta may still require imaging, blood-pressure management and specialist review. Follow-up helps the team identify changes and plan further treatment when necessary.

For non-emergency questions about known aortic disease or follow-up, you can explore my aortic awareness information and contact Andrew Choong Vascular Surgery. A family history of aortic disease may also warrant a discussion about appropriate assessment.

Current clinic location: Mount Elizabeth Novena Specialist Centre, #09-22, 38 Irrawaddy Road, Singapore 329563. Acute warning symptoms belong in an emergency service, where assessment and treatment can begin immediately.