Varicose veins (varices) are bulging, enlarged veins near the surface of the skin. They mostly occur in the legs.
Varicose veins develop when the small valves inside the veins stop working properly. Normally, one-way valves keep blood flowing up toward the heart and prevent if from flowing backwards (reflux). If the valves weaken or are damaged, the blood can flow backwards and collects in the vein. The preasure eventually causes the vein to be swollen and enlarged (varicose).
Varicose veins often run in families (90 % are inherited.
Subjective feelings of discomfort do no always respond to the size of varicose veins. People with large varicose veins can have no medical problems and contrarily.