Vascular diseases that affect veins include:
Deep vein thrombosis (DVT)
The formation of a blood clot in a vein deep in the leg. DVT can be fatal if a clot breaks away and blocks blood flow to the lungs or heart.
Bulging, twisted veins, usually in the calves and thighs. The condition commonly affects women, and does not usually cause serious health problems.
When veins have difficulty returning blood from the lower limbs to the heart, due to blockages or damaged valves. Blood can pool in the legs and feet, causing swelling and pain.