Last updated: 19 January 2012
Varicose veins are swollen and enlarged veins that are usually blue or dark purple. They may also be lumpy, bulging or twisted in appearance.
Varicose veins develop when the small valves inside the veins stop working properly. In a healthy vein, blood flows smoothly to the heart. The blood is prevented from flowing backwards by a series of tiny valves that open and close to let blood through. If the valves weaken or are damaged, the blood can flow backwards and can collect in the vein, eventually causing it to be varicose (swollen and enlarged).
How common are varicose veins?
Varicose veins are a very common condition, affecting up to three in 10 adults. Usually, women tend to be more affected than men.
Any vein in the body can become varicose, but they most commonly develop in the legs and feet, particularly in the calves. This is because standing and walking puts extra pressure on the veins in the lower body.
For most people, varicose veins do not present a serious health problem. They may have an unpleasant appearance, but they should not affect the circulation or cause any long-term health problems. Most varicose veins do not require any treatment.
For some people, varicose veins can cause aching, swollen and painful legs. In rare cases, they can also cause complications, such as skin discolouration and leg ulcers (see Varicose veins - Complications). Varicose veins are more likely to require treatment if they are causing significant discomfort or if complications develop.
There are now a number of different surgical procedures to remove varicose veins, although the first treatment is usually compression stockings. These are stockings that have been specially designed to squeeze the legs and improve circulation. See Varicose veins - Treatment for more information about the different treatment options.
Continue to next section: Symptoms of varicose veins