What causes varicose veins?
Leg veins normally allow blood to flow in an upward direction towards the heart.
This flow is aided by the pumping action of the foot and calf muscles (usually when walking). Valves within the veins allow blood to flow upward to the heart but usually close and prevent blood flowing backwards toward the feet under gravitational force. i.e. the valves are one way flow valves. Varicose veins develop when these valves stop working properly. As a result, blood flows in a reverse direction in the veins (called – an incompetent vein). This leads to higher pressure within the veins due to pooling of the blood and consequently varicose veins develop.
Varicose veins can occur in both men and women, but more frequently in women. Most commonly there is a family history of varicose veins caused by an hereditary weakness in the vein wall or vein valves.
In women pregnancy is a major causative factor. This is due to the hormone Oestrogen which relaxes vein walls, increased circulating volume of blood to supply the mother and baby and also the enlarged uterus which restricts the return of blood from the legs and allows pooling and increased vein pressures in the pelvis and legs.
Standing for long periods such as in occupations like nursing, hairdressing and hospitality are also thought to play a role in the development of Varicose Veins.
Obesity and trauma may also be causative factors.