Venous disease runs in families. The incidence increases with increasing age. There is an increased risk with pregnancy and other hormonal changes. Prolonged standing and obesity may also increase the incidence of venous disease.
What is the cause of Venous Disease?
To understand the cause, one needs to understand the anatomy and function of veins. Arteries are blood vessels that cary oxygen and nutrients to the body. Arteries in the leg carry this oxygen and nutrients to the skin, muscles and nerves. Once the oxygen and nutrients have been delivered, veins take the blood back to the heart. There are deep veins within the leg, a more superficial venous system (The Saphenous System) and a very superficial system (Subdermal veins). The saphenous system is usually the cause of chronic venous disease. These veins all take blood back to the heart, travelling against gravity. To ensure optimal return, the veins all have one-way valves which prevent blood from travelling towards the feet.
Venous disease starts to occur when there are defects along the vein wall which involves the valves. If the wall becomes weak, it dilates. At these points, the one-way valves no longer function properly as they are too small for the dilated vein and cannot maintain one direction of blood flow.
When this starts to occur, blood flows towards the heart and then comes back towards the feet due to gravity. This is called venous reflux. This reflux of blood causes the veins to be stretch and this causes pain, throbbing and heaviness as there are nerves around these veins. As the veins become more dilated, branches of the main system also become dilated from the increased pressure of the blood in the veins and varicose veins may become visible. This increased pressure is called "venous hypertension".
The veins are full of extra fluid (blood) which may extravasate into the tissues and this is when one experiences swelling around the ankle. Typically, this gets worse towards the end of the day and impressions by socks (or if a finger is pressed at the ankle) are created. Elevating the leg improves the swelling as the force of gravity is removed and blood can be returned tot he heart more easily. This is why swelling is often better in the morning when walking.
When fluid has escaped the veins and settles in the tissues around the ankles, some pigment called heamosiderin from the red blood cells may deposit in the skin causing darkening of the skin around the ankles. The body recognises all these events as abnormal and then tries to heal the problem by recruiting inflammatory cells - some of these producing histamine which causes itching.
Just as scar tissue forms from a cut, the same process to form "scar" tissue occurs in the legs underneath the skin. These cells are called fibroblasts. This fibrous tissue has been throughout to coat arteries and affect the delivery of oxygen and nutrients to the skin. The skin condition worsens in venous disease and the worst outcome is the development of an ulcer. These ulcers form typically on the inside of the ankle. These ulcers are quite troublesome as they prove difficult to heal. This healing process may take six months or longer.
What are the treatment options?