Lump on a leg vein: what is it and is it dangerous?

Most of the time, a lump on a leg vein is a varicose bulge: soft, painless, and it flattens when you lie down with the leg raised. The lump to worry about is one that has become hard, tender and warm, with red skin over it. That is how a clot inside a varicose vein (superficial thrombophlebitis) shows up, and it needs an exam with a vein ultrasound within the next few days. Only an ultrasound can reliably tell the two apart; a photo cannot.

A familiar scenario: in the evening you feel a small bump along a vein on your shin. The first thought is, what if it is a clot and it breaks loose? Let us calmly go through what these lumps can be and when you should not wait.

Lump on a vein in the leg: what is it?

When patients say "a lump on my vein", they can mean quite different things:

• A varicose bulge: a soft swelling of a widened vein just under the skin. This is the most common case, especially on the lower leg and the inner thigh.
• A clotted varicose vein (thrombophlebitis): a varicose bulge in which the blood has clotted. It is firm and tender, and the skin over it turns red.
• A widening of the vein in the groin where it joins the deep vein: it appears when you stand or cough and disappears when you lie down.
• Lumps that are not veins at all: a lymph node, a lipoma, a skin cyst, a bruise after a knock, or a cyst behind the knee. They can sit right next to a vein and look like part of it.
• A firm cord after sclerotherapy or endovenous laser treatment: a hard, sometimes tender line along the treated vein. Usually this is simply the vein sealing shut, and it fades gradually. Show it at your follow-up visit, and if the whole leg swells, contact your doctor the same day.

If a large stretch of vein has bulged rather than a single bump, see the page "Bulging leg veins". This article is about a single, localized lump.

A lump in the groin or behind the knee: why it needs an in-person exam

In the groin, where the great saphenous vein joins the deep vein, there can be a soft swelling that grows when you stand or cough and disappears when you lie down. It is easy to mistake for a hernia. Behind the knee, a lump may turn out to be the small saphenous vein, a Baker's cyst or, rarely, a widened artery.

Each of these is treated differently, so I always check such lumps with a vein ultrasound. It shows whether this is a vein, a hernia, a lymph node or a cyst, and whether there is a clot. If the lump turns out not to be a vein, I refer you to the right specialist surgeon.

Varicose lump on the leg: where it comes from and why it will not go away on its own

Leg veins have valves that let blood flow only one way: up, toward the heart. With varicose veins, the vein wall weakens and stretches, the valves stop closing properly, and blood runs back down when you stand. This can start in the main trunk of a superficial vein or in its side branches. Where the wall is weakest, the vein bulges out into a knot.

Typical features of such a bulge: it is soft, easy to press flat with a finger, bigger in the evening and in hot weather, and it collapses when you lie with the leg raised. It usually does not hurt, though it may ache after long hours on your feet.

This kind of bulge will not shrink away by itself: a stretched vein wall and failing valves do not recover. Compression stockings and vein tablets can ease heaviness and swelling, but they do not remove the bulge. On the other hand, a soft bulge without a clot is not an emergency, so you have time to book an ultrasound calmly.

Painful lump on a leg vein: a clot in the bulge and thrombophlebitis

If a lump suddenly turns hard, hurts when you press it, and the skin over it becomes red and hot, it most likely means a clot has formed in the bulge with inflammation around it. This is superficial thrombophlebitis; I cover it in detail in "Thrombophlebitis: is an inflamed vein urgent?".

A clot in a small varicose bulge is rarely life-threatening in itself. The real issue is that you cannot see from the outside where it ends. The clot can extend along the main superficial vein toward the groin or behind the knee, where the superficial vein joins a deep one, and sometimes there is already a deep vein thrombosis as well.

That is why anyone with a painful lump needs an ultrasound, even if the lump is small. Based on the scan, the doctor decides whether local treatment and compression are enough or whether blood-thinning medication is needed.

Home check: 5 questions to ask about your lump

This check does not give you a diagnosis, but it helps you judge how soon you need a doctor. Do it gently, without force.

1. 1Soft or hard? Press lightly with the pad of your finger. A soft varicose bulge flattens and then refills; a clotted one is firm and does not flatten.
2. 2Does it go down when you lie down? Lie for 10 to 15 minutes with your leg on a pillow. A varicose bulge gets smaller; a clotted one stays the same.
3. 3Does it hurt when pressed? A mild ache in the evening is typical of varicose veins; sharp pain at one spot is a reason to think of a clot.
4. 4Is there redness and warmth? Compare the skin over the lump with the skin nearby using the back of your hand, and look for a red streak running up along the vein.
5. 5Is it spreading? Outline the edges of the redness and the hard area with a pen. This is not a reason to delay the visit, but a reference point for the doctor. If the redness or firmness spreads beyond the line before your appointment, see a doctor the same day.

What to bring to the appointment: photos of the lump standing and lying down, the date it appeared, any injury, flight or bed rest beforehand, and a list of your medications, including hormonal contraceptives.

Lump on a vein: what to do before the exam and what to avoid

A common myth is that you should knead or warm the lump and it will dissolve. A soft varicose bulge will not disappear with massage or heat, and if there is a clot inside, rubbing and kneading it is pointless and painful. Until you have had an ultrasound, do not:

• pierce, squeeze or cut the lump: this leads to bleeding and infection;
• go to a bathhouse or sauna, take hot baths, or rub warming ointments on the bulge: overheating makes blood pool in the veins and the leg swell, and heat will not dissolve the bulge. A cold or warm compress through a cloth for 10 to 15 minutes is fine only to ease pain, and only if your doctor agrees;
• massage, knead or rub the bulge, especially if it is hard and painful;
• apply vinegar or alcohol compresses or folk-remedy wraps;
• start blood-thinning injections or tablets on a friend's advice: these are prescribed only after an ultrasound.

What you can do before the exam: walk more at an easy pace, avoid sitting still for hours, and rest with your leg slightly raised. If you already have compression stockings fitted for you, you can usually keep wearing them.

How to get rid of a lump on a leg vein

Treatment starts with an ultrasound, because the bulge is often just the visible tip of the problem. If the backward flow comes from the trunk of the great or small saphenous vein, that trunk is usually treated too; otherwise new bulges are more likely to appear nearby. Sometimes it is enough to remove only the widened side branches and keep the main vein. I choose the treatment method only after the ultrasound.

• Mini-phlebectomy: the bulge is removed through skin punctures a few millimeters long under local anesthesia, with no stitches. It suits large, twisted bulges.
• Sclerotherapy: a medication is injected into the vein, as a liquid or a foam; the vein walls seal together and the vein is gradually absorbed. It suits small bulges and side branches.
• Endovenous laser ablation (EVLA): if the source is in the trunk of a superficial vein, the trunk is closed from the inside with a laser, and the bulges are removed the same day or at a second stage.
• A clotted bulge is first treated as thrombophlebitis. Planned removal of the bulge comes after the inflammation has settled.

I discuss the scope of treatment and its cost after the ultrasound and give you a written estimate. No method comes with a lifetime guarantee: varicose veins are a chronic condition, so follow-up visits are needed after treatment.

When to see a doctor urgently

See a phlebologist or a surgeon the same day if you have even one of these signs:

• a painful hard area along a vein on the thigh, especially close to the groin, or behind the knee: this is where the superficial vein joins the deep one;
• redness and hardness spreading fast: within a few hours they have gone past the line you drew with a pen;
• a red, painful streak running up along the vein;
• a painful lump that appeared during pregnancy or in the first weeks after giving birth, after recent surgery or bed rest, alongside cancer, in someone who has had a deep vein thrombosis before, or on a vein that was not varicose before;
• the whole lower leg or the whole leg has swollen, or there is a bursting pain in the calf;
• the skin over the bulge has become thin and bluish, or a dark crust has formed: there is a risk of bleeding;
• a lump behind the knee or in the groin pulses in time with your heartbeat;
• redness spreads across the skin as a patch with sharp edges, with fever and chills: this may be the start of erysipelas, a skin infection, rather than thrombophlebitis.

Call an ambulance (103 in Uzbekistan) if the bulge is bleeding and the bleeding does not stop with pressure, or if you suddenly have shortness of breath, chest pain, are coughing up blood, have a racing heart or faint. If a vein is bleeding: lie down, raise the leg above heart level, and press firmly on the spot with a clean cloth or bandage without letting go for several minutes. Do not apply a tourniquet. Step-by-step instructions are in "Bleeding from a varicose vein".

Bottom line. A soft lump that goes down when you lie down and does not hurt is almost always a varicose bulge: a reason for a routine ultrasound, not for panic. A hard, painful, hot lump is a reason for an ultrasound within the next few days, and on the same day if you have any of the signs listed above. Do not heat, knead or pierce the bulge.

Not sure? Call and I'll tell you how urgent your situation is: +998 99 883-93-21

This article is for informational purposes only and does not replace a consultation with a qualified physician. If you are experiencing symptoms, please see a specialist.