Varicose veins occur when veins are not normally returning blood from the legs to the heart. Veins have one way valves that allow blood to flow only towards the heart preventing backflow in the legs. When the valves do not function well, blood does not flow efficiently and "Reflux" towards the foot. The veins under the skin become congested, dilate and bulge on the surface. There are two types of varicose veins: primary and secondary.

In primary varicose veins the pathological process begins in the superficial venous system. Venous wall weakness and valve insufficiency are the main factors. The cause of this process is unknown but many factors play a part in their development:

	Genetics: heredity is a significant factor. In many cases they seem to run in families. If your father or mother has varicose or spider veins, there is greater likelihood you will develop these abnormal veins. Identical twins, in fact, may be affected in the same area of the body and to the same extent. It is possible that there is an inherited weakness of the vein walls and congenital deficiency in the number of venous valves.
	Gender: females are affected four times more than males.
	Pregnancy: during pregnancy varicose veins may form but may also disappear shortly after delivery. Circulating hormones increase the dispensability of vein walls; increase in venous capacity to accommodate a greatly expanded circulating blood volume and later in pregnancy the enlarged uterus tends to compress veins in the pelvic area and that causes the leg veins to distend and become noticeable. Treatment of varicose veins prior to pregnancy helps prevent progression during pregnancy.
	Birth control pills may affect the veins wall causing distention and valve damage.
	Life Style/Occupation: people who are involved with prolonged sitting or standing in their daily activities have increased risk of developing varicose veins. Women seem to be more susceptible to this problem because vein walls and valves periodically become more dispensable under the influence of cyclic increases in progesterone.
	Wearing tight girdles, corsets or hosiery held with tight rubber band.
	High heel shoes.
	Lack of exercise.
	Chronic Sun Exposure may cause spider veins on the face, nose & cheeks of fair skinned persons.
	Age: Varicose veins can occur at any age but usually start between the ages of 18 and 35, and peaks between 50 and 60 years. Advancing age leads to weakened vein wall that is more susceptible to dilatation and varicose vein formation.
	Obesity & weight fluctuation.
	Chronic constipation and low dietary fiber may cause varicose veins to appear.
	Trauma and Surgical incisions may lead to new blood vessels and development of spider veins.

In secondary varicose veins the pathological process starts in the deep system. Deep Vein Thrombosis (DVT), congenital valvular dysplasia, obstruction, tumor, venous malformation, arterio-venous fistulae are known cause increased backflow of blood in the perforating veins to the superficial venous system. Treatment of secondary varicose veins is different from primary veins and should be directed to the cause and not the varicose veins.