Spider veins, medically known as telangiectasias, are small dilated blood vessels near the surface of the skin, measuring less than 1 millimeter in diameter. The vessels have damaged the vein walls and are not functioning normally.
Phlebitis simply means inflammation of a vein. Most cases of phlebitis in the legs are due to thrombosis (blood clots), called thrombophlebitis. The two primary types of thrombosis are superficial vein thrombosis (SVT) and deep vein thrombosis (DVT).
Varicose veins come in many forms. They can be visible in various sizes of protruding, rope-like veins. These often become more prominent with prolonged sitting or standing. Some varicose veins may primarily be noticed by feeling a series of knots or indentions in the leg just below the skin surface.
Venous ulcers account for up to 90% of leg ulcers. Ulcers are non-healing or poorly-healing open skin wounds. The most common site of venous ulcers is on the inner part of the leg just above the ankle. They may also occur on the shin and other areas surrounding the ankle.