Venous insufficiency is a general term to describe abnormal venous return. There are three causes of venous insufficiency:
1. Reflux: Reflux is when faulty vein valves allow the blood to flow backwards and is the most common cause of venous insufficiency. Contributing factors include:
Heredity: This is the most common cause of venous insufficiency.
Gender: Women are more likely to develop varicose veins due to the effect of female hormones during menstruation, pregnancy, and menopause, as well as hormone replacement therapy/birth control pills
Pregnancy: The physical changes associated with pregnancy have great effects on the lower extremity circulation. The enlarged uterus and increased blood volume increases weight and pressure on the veins in the legs and hormonal changes relax vein walls leading to dilation. Multiple pregnancies increases the risk.
Congenital disorders affecting venous formation and function
Occupational hazards: people who work on their feet (Nurses, teachers, flight attendants) and those who do a lot of heavy lifting (weight lifters, heavy duty mechanics).
2. Obstruction: Trauma, either direct (bad fracture/blunt force trauma) or indirect (deep vein thrombosis) can cause physical remodeling and failure of the valves and vessels. Blood clots can block the flow of blood within the veins causing damage and scarring of the vein valves. This can happen with superficial thrombophlebitis and with deep vein thrombosis.
3. Failed muscle pump: Long periods of bed rest or inactivity will decrease the amount of blood that is propelled back to the heart by the calf muscles leading to pooling in the extremities.
Venous insufficiency is categorized by a CEAP score rated from 0 to 6. The rating is based on physical signs of disease only.
The failure of the greater saphenous vein valves is a major cause of varicose veins. This means that the varicose veins on the lower thigh, around the knee and in the calf are usually caused by a failure of the valves much higher up. Unless these hidden veins are treated, it is difficult, if not impossible to achieve the desired results.
This disease process can affect veins of any size, however, when larger veins fail, they are typically called varicose veins. When smaller veins are affected, they are called spider veins.