Risk Factors and Causes of Varicose Veins
Risk factors for varicose veins include the following:
- Gender (more common in women)
- Heredity (genetics)
- Hormonal factors (e.g., pregnancy, menopause)
- Trauma to the lower extremities
Age is a risk factor, for both women and men. During aging, the elasticity or tone of the veins decreases, increasing the risk for dilation. Once dilation occurs, the leaflets of the valve within the vein are pulled apart by the expanding vessel walls and can no longer form a tight seal.
Women are at increased risk for developing varicose veins. The condition occurs in approximately 25 percent of women, compared with 15 percent of men. This increased risk is mostly due to hormonal (e.g., estrogen, progesterone) factors that are affected by pregnancy, menopause, and the use of birth control pills.
Heredity is an important risk factor. The chance of developing varicose veins doubles if a parent has the condition. If a family member has varicose veins, the risk for developing the condition is about 40 percent in female relatives and about 20 percent in male relatives.
Pregnancy itself is an additional risk factor. During pregnancy, the enlarged uterus causes pressure on the veins in the pelvis, which in turn results in increased back pressure on valves within the leg veins. This increased pressure can also lead to hemorrhoids, which are varicose veins of the rectum. Commonly, varicose veins worsen with each additional pregnancy.
Obesity increases the risk for varicose veins because of additional weight on the veins and the increased pressure on the circulatory system.