How varicose veins form

It is the veins that lie outside the muscle, not the deep veins, that become varicose. There are two theories about how varicose veins form and perhaps both are true.

The old theory says that the basic cause is failure of the valve at the connection with the deep vein in the muscle. Over time, the superficial vein will swell to cope with the extra blood, lose its elasticity and become a lumpy, blue, varicose vein. The swelling means that the next valve below will eventually be unable to close, because its edges will no longer meet each other in the closed position. So there is a domino effect, with each damaged valve eventually producing damage to the one below it. As it does so, more of the vein will swell and become varicose. This would happen very slowly over years.

A newer theory, gaining ground among experts, says that the vein wall is inherently weak in people who get varicose veins. The vein swells and so the valves do not work properly.

Symptoms of varicose veins
Varicose veins are a problem for three reasons.

• They look ugly, because the affected veins are just below the skin, and the enlarged and twisted portions are very obvious.
• The pools of non-circulating blood cause symptoms.
• Bad varicose veins over many years can damage the skin near the ankle, causing eczema – the skin becomes stained brownish-black, and ulcers may occur which are difficult to heal.
  

Lots of symptoms, such as swelling, restless legs, cramps, tingling and aching, have been linked to varicose veins. A study in Edinburgh tried to find out the truth, by asking 1566 people about their symptoms (British Medical Journal 1999;318: 353–6). They discovered that, in women, varicose veins can cause a heavy feeling in the legs, aching and itching. In men, however, itching seems to be the only symptom. A feeling of swelling of the legs, cramps, tingling and restless legs are probably not actually caused by varicose veins, but may have other causes (such as ageing).