12/22/2009 - Questions and Answers

Thrombosed varicose vein

By: Mark Castleden


My left leg is swollen below the knee. And there's a lump, like a knot. Sometimes it's hard to walk. What's it due to?


My left leg is swollen below the knee. And there's a lump, like a knot. Sometimes it's hard to walk. What's it due to?


I assume the sore knot is in the area of your calf muscle. This could well be a non-functioning varicose vein or an inflamed varicose vein.

A varicose vein is a large and winding blood vessel. These twisted, swollen and bulging vessels are commonly found on the insides of the legs and at the back of the calf and are visible on the surface.

They form because the blood flow is too slow and the vein fills up with the excess. Another possible reason is that the valves in the vein are not working properly so the blood drops down from gravity and collects in the veins of the legs. Nearly 15% of all adults are affected. Varicose veins are more likely to occur in women than in men.

Leg veins become bigger, blue and twisted. Most people feel some pain in the area, with swelling, and a constant itch. Blood pooling in the veins means the tissues don't get enough blood and nutrients, causing the skin to become thin, hard, dry and discolored.

Ulcers may also form in the area. Sitting down with the legs raised is the only way that these problems will be relieved. Bumping can cause severe bleeding so contact with the vein should be limited.

The legs have of two systems of veins - deep veins, which carry about 90% of the blood, and the surface veins, which are visible just below the skin and are not as well supported.

After the blood has gone through the tissues in the leg it is pumped back up through the leg and up to the heart. As the blood is pumped upwards, there are valves in the veins that prevent the blood from falling back down the leg. If these valves become defective the blood will pool and flow back down the leg causing superficial varicose veins to form. These become swollen and distorted. Obesity and hormonal changes during pregnancy contribute to the formation of varicose veins.

Deep vein thrombosis is sometimes associated with varicose veins. Superficial vein thrombosis can also happen on the surface, producing the symptoms that you describe. It's very possible that a venous clot can form giving you the sensation of a sore, full, knotted area. If this sore area that you describe becomes red and extremely sore to the touch don't delay - see your doctor as soon as you can.

Created on: 09/12/2002
Reviewed on: 12/22/2009

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Anonymous wrote 2 years 19 weeks ago

Thorough explanation of a possible diagnosis.

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