Spider veins are also known as broken capillaries. Spider veins are tiny blood vessels no more than 2 mm in diameter that may appear on the face, legs and ankles. They are bluish, purple or red and often form a web-like netting just below the skin s surface. Spider veins are generally just an unattractive nuisance, although when they become large they can cause heaviness in the legs, night cramps and itching. Varicose veins are veins near the surface of the skin on the legs which have become permanently distended and filled with blood.
Veins have valves that are designed to prevent blood from flowing backwards due to gravity.
When a valve malfunctions or vein walls weaken, blood collects in the vein, forcing it to bulge. Varicose veins are unsightly, bluish or purple in color and can protrude from the leg. They may cause discomfort such as swelling, throbbing, heaviness, night cramps and long-term complications such as ulcerations or bleeding. For both varicose and spider veins, heredity is the main cause. The risk of developing these leg vein problems increases for women who are pregnant or using birth control pills because hormones such as estrogen can further weaken vein walls.