Are Varicose Veins Dangerous, or Just a Cosmetic Problem?
Most varicose veins are harmless to life but not harmless to the leg. Here is how to tell which kind you have.
Short answer: varicose veins are rarely life-threatening, but they are not purely cosmetic either. For some people they cause no symptoms and the only concern is appearance. For others they cause aching, swelling and night cramps, and over years they can lead to skin damage, ulcers, bleeding and superficial clots. The distinction is made not by how the veins look but by your symptoms and by a duplex ultrasound, which shows how much reflux there is and whether the deep veins are involved.
When are varicose veins only cosmetic?
Thread veins, spider veins and small reticular veins on the thigh or behind the knee are almost always cosmetic. Larger varicose veins can also be purely cosmetic if they cause no aching, swelling, itching or skin change, and if the scan shows only limited reflux in a small tributary rather than in one of the main saphenous trunks. In that situation there is no medical need to treat, and the choice is yours. Treatment for appearance alone is generally not covered by insurance.
When do they become a medical problem?
International guidelines treat varicose veins as a medical condition when they are accompanied by any of the following:
| Finding | Why it matters |
|---|---|
| Aching, heaviness, throbbing, itching or night cramps that are worse after standing and better with elevation | Symptoms of venous hypertension; treatment is intended to relieve them |
| Ankle swelling by the end of the day | Fluid is being forced into the tissues by venous pressure (CEAP C3) |
| Brown staining, eczema, hardening or white patches around the ankle | The skin is being damaged (C4); the next stage is an ulcer. See skin darkening and ulcers |
| A healed or open ulcer on the lower leg | C5 and C6 disease; guidelines recommend treating the reflux |
| A bleed from a varicose vein | A recognised complication; the vein should be treated. See bleeding varicose veins |
| A hard, tender, red cord along a vein | Superficial vein thrombosis, which can extend into the deep veins |
Can varicose veins cause a blood clot?
Varicose veins themselves are not the same as deep vein thrombosis, and most people with varicose veins never have a clot. There are two real connections, however. Blood that pools slowly in a large varicose vein can clot within that surface vein, producing a painful, hard, red lump along its course. This is superficial vein thrombosis. It is usually self-limiting, but if the clot lies close to where the surface vein joins the deep system it can extend inwards, and guidelines recommend a duplex scan to check and, in some cases, a short course of anticoagulation. Separately, large population studies have found that people with varicose veins have a somewhat higher rate of deep vein thrombosis than those without, although the reasons are not fully understood. Read more about the difference between varicose veins and DVT and the warning signs of a deep vein clot.
How does a scan tell the difference?
Looking at the leg tells you the veins are varicose; it does not tell you why, or how significant the problem is. A duplex ultrasound, done with you standing, shows which veins are refluxing, for how long, how wide they are, whether the deep veins are open and competent, and whether there has been a previous clot. From that the surgeon can place you on the CEAP scale, judge whether treatment is likely to help, and, if so, choose the method. The scan is painless, takes around twenty to thirty minutes for both legs and is normally done at the first visit.
Should I treat them if they do not bother me?
If you have no symptoms, no skin change and the scan shows limited reflux, there is no medical reason to treat and watchful waiting is reasonable; compression stockings for long days on your feet are a sensible precaution. If the scan shows significant saphenous reflux, treatment can be discussed as a way of preventing later skin damage, but it is not urgent and the decision can be made in your own time. If there are symptoms or any of the findings in the table above, treatment is recommended, and the options are set out on the treatment options page.
Common questions about whether varicose veins are dangerous
Can varicose veins cause a stroke or heart attack?
No. Varicose veins are a disorder of the superficial leg veins and have no direct connection with the arteries of the heart or brain. The main risks they carry are to the skin of the leg, from bleeding, and from clots in the surface veins.
Do varicose veins get worse if left alone?
Usually slowly, yes. Reflux tends to progress over years, and large studies following people with untreated varicose veins show that a proportion move up the CEAP stages to swelling and skin change. The pace varies a great deal between people, and some never progress.
Is it dangerous to fly with varicose veins?
Not in itself. Long flights raise everyone's risk of a deep vein clot slightly, and that applies to people with varicose veins too. Wearing compression stockings, moving your calves regularly and staying hydrated are the standard precautions.
Can exercise make varicose veins worse?
No. Walking and calf exercise push blood up the leg and relieve venous pressure; they are recommended. Heavy straining with the breath held can raise pressure in the veins briefly, but there is no evidence that normal exercise causes or worsens varicose veins.
Scan first, then decide
The only reliable way to know whether your veins are cosmetic or medical is to look inside them. A duplex ultrasound at a first visit maps which veins are faulty, usually on the same day, and you leave with a plan. Read about what a first visit for varicose veins involves, or arrange one:
Sources: European Society for Vascular Surgery 2022 clinical practice guidelines on chronic venous disease; NICE CG168 Varicose veins: diagnosis and management. Full references are listed at the end of the varicose veins page.