Varicose Veins: Causes and Risk Factors

What is the main cause of varicose veins? The answer, unfortunately, is not a simple one. In general, primary varicose veins develop with or without a specific cause and are usually a result of congenitally defective valves in the superficial veins. Secondary varicose veins, on the other hand, occur because of another condition, such as pregnancy or menopause.

Most Common Causes

Several theories exist regarding the cause of varicose veins. The most common are described here.

Valvular Dysfunction

Valvular dysfunction occurs when the valves, located at intervals throughout the superficial veins, fail to function properly. Valvular dysfunction and poor circulation may result in blood, which should have been carried back to the heart for re-oxygenation in the lungs, pooling in the veins and causing vessel widening.


Loss of elasticity and weaknesses within the blood vessel walls increase with age. Typically, such weaknesses develop between the ages of thirty and seventy and are a common cause of varicose veins.

Poor Circulation

A poor circulatory system is often to blame. Inactivity and lack of exercise can result in weakening or wasting of the muscles and poor circulation. Wearing restrictive clothing such as panty-girdles can also inhibit circulation and cause the formation of blood clots, particularly in the legs.

[su_pullquote align=”right” class=””]A Common Myth
Prolonged standing or sitting in one position, or sitting with your legs crossed for any length of time does not cause varicose veins. Such immobility, however, does tend to exacerbate the condition![/su_pullquote]


Genetic predisposition is a known cause. This relates primarily to hereditary weaknesses in the blood vessel walls or valves.


Being overweight puts extra pressure on the legs, making it more difficult for the blood to flow back to the heart. People who are overweight tend to have less muscle tone, which also contributes to worsened circulation.

Hormonal Changes

A fluctuation in the level of hormones, commonly associated with pre-menstruation, pregnancy, menopause, or use of oral contraceptives can trigger the development of the condition.


The increased pressure on the abdomen and pelvis experienced during pregnancy can cause the onset of varicose veins. Fortunately, the condition is usually temporary and, in most cases, resolves itself within a few weeks of delivery.


The increase in straining during bowel movements that result from a low-fiber diet places excessive pressure on the blood vessel walls. This extra pressure may cause damage to the wall linings and/or valves, thus increasing the risk of developing varicose veins.


A contusion or simple blow to the leg can be a cause of varicose veins.


In summary, your risk of developing varicose veins increases if several of these factors apply to you:

  • Genetic predisposition
  • Increasing age
  • Excess weight or obesity
  • Lack of exercise
  • Poor diet
  • Fluctuating hormones
  • Oral contraceptive use
  • Injury