Why these veins and valves fail is not completely understood. It may be due to a weakness in the valve itself or in the vein wall. There are a number of factors that may lead to varicose veins:
Heredity – This is the most important factor, if your parents and grandparents have varicose veins then you have an increased likelihood of developing varicose veins.
Gender – Women seem to have a higher incidence of varicose veins due in part to the female hormones affecting the vein walls.
Pregnancy – This causes a rise in blood pressure and volume and also adds to the hormonal effect mentioned above.
Age – As we age our tissues loose elasticity causing the valve system to work less well.
There are additional factors that do not cause varicose veins, but may speed up their development or make them worse:
Obesity – Increases in weight often go hand in hand with increased blood pressure. This may add to vein problems.
Prolonged standing – The volume and pressure of blood in the lower limbs is affected by gravity, so the longer you stand the greater the effect.
Prolonged sitting – As with prolonged standing, the volume & pressure of blood in the lower limbs is affected by gravity, so the longer you sit the greater the effect.
Physical trauma – Sometimes trauma to the lower limbs can damage the underlying blood vessels and add to the problem of varicose veins.