Dilated twisted veins just under the skin that lead to pain, swelling and sometimes ulceration. They develop from faulty valves in the vein wall that weaken the vein wall leading to dilatation and reflux. The heart pumps blood rich in O2 and nutrients to the whole body - arteries carry blood from the heart to the body parts. Veins carry O2 poor blood from the body back to the heart. The calf muscles function as the “venous” heart when the muscles contract they push blood in the veins back to the heart. The veins have one-way valves that keep the blood from going backward down the leg. When the valves fail, blood moving backwards is called reflux. Reflux is the cause of venous insufficiency and varicose veins. Reflux can be compared to a backed up pipe where the high pressure in the abnormal vein increases the pressure in the normal veins causing them to dilate and deteriorate.
The deeper veins are externally supported by muscle and can withstand much higher pressures than superficial veins,which are not supported.When pressure from the deep veins are transmitted to the superficial veins they become stretched and elongated or varicose.(latin:swollen or knotted).
Spider veins or telangiectasia are small thread like veins in the skin that are connected to the larger venous system. They begin as capillaries, are blue or red, and look like a spider web or as branches of a tree. They are caused by reflux: pressure from the deeper vein to the fragile skin veins. They can be a cosmetic problem or cause throbbing and aching. The treatment is to first eliminate all cause of reflux and then usually sclerotherapy is used to eliminate the visible veins.