Veins are the soft, thin-walled tubes that return blood from the arms and legs to the heart. Because veins work against the force of gravity, they have valves that allow forward blood flow, but not reverse. Your legs and arms have two major types of veins: superficial and deep. The superficial veins are near the surface of the skin and are often visible. The deep veins are located near the bones and are surrounded by muscle. Connecting the deep and superficial veins is a third type of vein, the perforator vein. Contraction (squeezing) of the muscles in the arms and legs with exercise helps blood flow in the veins.  
 
Varicose veins are enlarged, bulging superficial veins that can be felt beneath the skin, generally larger than 3-mm in diameter. They are usually located on the inside of the calf or thigh and develop due to weakness of the vein wall and loss of valve function. Under the pressure of gravity, they continue to enlarge, and in the course of time, they may become elongated, twisted, pouched, and thickened.
 
Spider veins or telangiectasia are tiny dilated, veins, usually less than 1-mm in diameter, located at the surface skin layers. Spider veins cannot be felt. Veins larger than the spider veins, but still under 3-mm are called reticular veins. Varicose veins may be entirely symptom-free and cause no health problems. Treatment in such cases is often for cosmetic purposes. When symptomatic, varicose veins may cause ankle and leg swelling, heaviness or tension, aching, restlessness, cramps, and itching. Varicose veins are more often symptomatic in women than in men. Signs of chronic venous disease include skin pigmentation (usually rusty brown), and loss of the soft texture of the skin and underlying tissue in the ankle area (called induration). Itching is perhaps the most consistent symptom of varicose veins in men. Women most often complain of leg heaviness, tension, and aching.

Causes of Varicose Veins

The causes of varicose veins may be primary, secondary, or congenital. Varicose veins of primary cause develop as a result of an inherent weakness in the wall of the vein. Varicose veins can have a hereditary factor and often occur in several members of the same family. Varicose veins that develop after trauma or deep vein thrombosis are of secondary cause. Congenital varicose veins are due to disorders in the natural development of the venous system, and usually are part of a vascular malformation in the limb, present at birth. In addition to varicose veins, these individuals may also have an enlarged and longer limb and often have birthmarks (port-wine stains), like in Klippel Trenaunay Syndrome (KT syndrome).  No matter the cause, defective venous valves may cause venous blood to stagnate in the leg, leading to increased pressure in the veins. This may result in further enlargement of the varicose veins, increasing the likelihood of symptoms, and causing complications such as skin changes and ulcer formation. Blockage of the pelvic veins may severely aggravate the effects of varicose veins, requiring a separate treatment.

Risk Factors for the Development of Varicose Veins

The most important factors leading to the development of varicose veins include:

•          Heredity

•       Prolonged standing

•          Increasing age

•          Heavy lifting

•          Prior superficial or deep vein clots

•       Female gender

•          Multiple pregnancies

Less physical activity, a higher blood pressure, and obesity have also been linked with the presence of varicose veins in females.