In healthy veins, one way valves direct the flow of venous blood in the leg upward toward the heart. When one or more of these valves fails to function, the blood in the malfunctioning vein flows in the reverse direction, causing the veins under the skin to engorge and distend. The “back up” of blood flow increases the pressure in the veins to a level that is three to four times the normal amount. This high pressure then causes the veins to bulge and stretch and usually results in inflammation and pain.
Varicose veins do not occur suddenly. It can take years for signs and symptoms to develop. While genetics and inheritance play a big role in their occurrence, anyone can develop them even without a family history. They commonly occur during pregnancy and in people that have had certain types of leg injuries or deep vein blood clots. People that work in jobs that require prolonged standing or sitting are also at higher risk. A physical exam, along with an ultrasound, is necessary to determine the extent and severity of the varicose veins and if the varicose veins are caused by broken valves in the veins underlying the skin. Although less common, it is possible to have varicose veins and not experience painful symptoms.