Any problem that increases pressure in the veins in the legs can stretch the veins. This can damage the valves, which leads to even higher pressures and worsened vein function, and can eventually lead to chronic venous disease.
The pressure inside the veins can increase for a number of reasons, including:
- A clot inside a vein – A clot will block blood flow through the vein and cause pressure to build up. Often this causes permanent damage to the vein or valves, even after the clot has dissolved.
- Leg injury or surgery – Injury or surgery that blocks the flow of blood through a vein can increase pressure.
- Excess weight or weight gain – The added weight of pregnancy or obesity can increase pressure in the veins of the legs, and damage the veins and valves.
- Standing or sitting for too long – Standing or sitting for prolonged periods without walking can decrease the movement of blood out of the legs and lead to increased pressure in the veins and pooling of blood. That’s because the muscles in the legs play an important role in the circulation of blood, acting as a pump to move blood from the legs back to the heart.
Many other factors are associated with development of varicose veins including obesity, pregnancy, prolonged sitting or standing, or obstruction of veins in the abdomen or pelvis.
As veins stretch, the one-way valves in the veins fail allowing blood to run away from the heart due to the effects of gravity. This valve failure results in increasingly high pressure in the veins and worsening stretching of the veins. This process is called venous insufficiency and the abnormal downward flow of blood in the veins is called reflux.
Varicose veins may cause no symptoms at all. They may be associated with pain, tenderness, swelling at the ankle or calf, or brown-pigmented skin or a rash at the ankles or calves.
Varicose veins may be treated a number of different ways depending on the location, size, and shape of the abnormal veins. Elastic compression stockings are helpful in management of varicose veins and may slow down progression, but patients with varicose veins will ultimately need such procedures as ultrasound guided sclerotherapy, endovenous ablation, or microphlebectomy.