Arterial disease certainly gets its share of attention nowadays, and deservedly so. Atherosclerosis, which causes heart attacks and strokes, is the most serious medical problem in developed countries. Health topics like exercise, obesity, blood pressure and cholesterol control are important largely because of their impact on our arteries. By contrast, most of us know less about veins and the disorders that affect them. In this article we'll try to correct that. But first we'll need a brief lesson in anatomy and physiology.

Where Veins Fit In
The circulatory system consists of the heart, which pumps the blood; arteries, which deliver blood to tissues and organs; the capillary bed, a microscopic web of porous channels through which oxygen and nutrients are exchanged; and veins, which return blood to the heart. The part of the system that supplies the body as a whole is called the systemic circulation. The part that receives depleted blood from the body and pumps it to the lungs for re-oxygenation is called the pulmonary circulation.

As the heart contracts with each beat it forces blood through the arteries under high pressure. To accommodate this pressure and help propel blood forward, the walls of arteries contain a thick layer of muscle. The walls of veins, however, contain little muscle and are therefore much thinner and more distensible.

Veins in the lower body, especially the legs, face a battle against gravity. They get help in two important ways. First, surrounding muscle movements act as a pumping mechanism that squeezes the veins and pushes blood forward. Second, many veins contain delicate valves along their length. Each valve consists of two opposing folds of tissue. The valves keep blood moving in the right direction and prevent backflow.

With this background, let's take a look at some of the more common things that can go wrong with our veins.

Inflammation and Clots
When a vein becomes irritated or injured, inflammation can occur. The resulting syndrome is known as phlebitis. Inflammation is virtually always accompanied by a clot, or thrombus, within the vein; thrombophlebitis is therefore another name for this condition.

If phlebitis affects a small vein close to the skin surface, it is called superficial phlebitis. It is recognized as a reddened, swollen area that is tender to the touch. Sometimes the involved vein can be felt as a linear, cord-like structure. Any vein can be affected, but varicose veins in the legs are particularly vulnerable. Another common location is at the site of an intravenous line. Superficial phlebitis is usually not serious. The standard treatment consists of warm compresses and anti-inflammatory medications like aspirin or ibuprofen.

Phlebitis in a large deep vein is called a deep venous thrombosis (DVT). Almost always the involved vein is in the leg or pelvis. Pain and generalized swelling occur in the involved leg, but visible redness is usually not present. A DVT is always serious because a clot fragment can break off and lodge in the lungs, causing a potentially life-threatening syndrome called a pulmonary embolus. A DVT must be treated with potent anticoagulant medications and often requires hospitalization at first.

Incompetent Veins
Some people lack normal vein valves. In others, the valves break down over time or are injured as the result of phlebitis episodes. In either case, vein function becomes less efficient and pressures build up. Varicose veins are one consequence. But though unsightly and sometimes uncomfortable, varicose veins rarely cause harm.

A more important result of incompetent vein function is the syndrome of venous insufficiency, sometimes called venous stasis. In its mildest form, venous insufficiency simply manifests as the mild foot and ankle swelling we so commonly see in older people. The swelling is caused by fluid leakage into the tissues due to high venous pressures.

When venous insufficiency is more advanced, extensive swelling may extend into the calves or even the thighs. The skin of the feet and ankles may become discolored due to iron deposits from leaked red blood cells. A red, scaly rash called stasis dermatitis can complicate the condition. At its worst venous insufficiency causes deep leg ulcers that are very difficult to heal.

The simplest treatment for venous insufficiency is to harness gravity by elevating the legs. Prolonged sitting with the legs down should be avoided. Walking exercise is encouraged because the muscle activity helps propel blood out of distended veins. Specially prescribed elastic stockings can help by creating a pressure gradient that deters venous blood pooling. The skin manifestations of the disorder may require topical ointments or specialized wound dressings.

Finally, it is a common mistake to assume that leg swelling always requires diuretic medications ("water pills.") In the case of venous insufficiency, the problem is accumulation of blood and fluid in the legs, not too much fluid in the body as a whole. Judicious use of diuretics may sometimes be appropriate, but depending on these drugs as the mainstay of treatment can lead to dehydration.

May 2004