There are two sets of veins which carry blood from the feet back to the heart and lungs. The superficial veins are located just beneath the skin, and are often visible as enlarged or varicose veins. The second network of veins are the deep veins which are located close to the bone of the leg and thigh, and are not visible. Each of these sets of veins has the potential to develop a blood clot.
A blood clot is referred to as a thrombosis. When a blood clot forms there is usually an inflammatory reaction. An inflamed vein is called phlebitis. The inflammation causes swelling, pain, redness, and warmth along the course of the vein. Because these two events (blood clot and inflammation) almost always occur together, the terms venous thrombosis and thrombophlebitis are both used to refer to a blood clot in a vein.
Under normal circumstances blood does not form a clot in the vein. There are certain things, which will make a clot more likely to occur. For example, some families have an unusual trait, which causes their blood to clot more than normal. This is a hereditary abnormality. More common causes of blood clots would include a direct injury to the vein, oral birth control pills, long hours of sitting (for example truck drivers), a recent surgery, prolonged periods of bed rest, a recent pregnancy, or the presence of some types of cancers. Each individual with a blood clot should be evaluated for the underlying cause.
When a thrombosis (blood clot) forms in a superficial vein in the foot or leg it is recognizable as a linear, firm cord. That is because these veins are inflamed and swollen, and because they are located just beneath the skin. They may appear red and feel warm from the inflammation. They are usually painful and very tender to pressure. Classically in the legs, these occur along the course of the greater or lesser saphenous veins. A blood test to evaluate white blood cells may be necessary to differentiate superficial phlebitis from cellulitus (an infection under the skin which can also lead to pain, swelling, and redness of the foot or leg).
Superficial phlebitis, although painful, is not a serious condition. This condition should be evaluated by your doctor to rule out other more serious problems. Treatment usually involves the use of anti-inflammatory medication, elevation of the foot and leg, and warm compresses applied over the area of inflammation. Diabetic patients should not use heating pads or warm compresses unless they are supervised by their treating doctor.
Deep Vein Thrombosis
Although occasionally asympotomatic, most people with deep vein clots complain of pain, swelling, and warmth of the leg. There may be swollen superficial veins as well. The leg pain and soreness is worse with standing or walking, and feels better with rest and elevation. When the area is examined there is often severe tenderness with deep pressure, although this could also be found with muscular problems in the same location.
Confirmation of a suspected deep vein thrombosis can be made by ultrasound testing or by venogram. These tests are important because it is sometimes difficult to establish the diagnosis without them. A proper diagnosis is essential with deep vein clots because failure to properly treat these can result in chronic venous insufficiency or a life threatening pulmonary embolus.
Most patients with deep vein thrombosis require hospitalization. In this setting the patient will be given a blood thinner to prevent blood clots from spreading in the leg veins, and to prevent pieces of the clot (emboli) from traveling up to the lungs. Traditionally, heparin has been the blood thinner used in this situation. Other clot dissolving medications are now sometimes added to this treatment to prevent long term damage to the veins, thereby helping to preventing chronic venous insufficiency. Care must be taken with all these medication because they can result in serious undesirable bleeding. An additional treatment, which may be recommended, is a filter, which is surgically placed into the large vein returning blood to the heart. This filter is to prevent pieces of clots from traveling from the leg veins up to the heart and lungs. Clots in the lungs can cause death.
Once the patient has been stabilized, the heparin is discontinued and an oral blood thinner called warfarin (Coumadin) is used. This is usually continued for several months depending upon the severity of the episode, and the patient. Periodic blood tests are required to monitor the bleeding and clotting ability of the patient. The dose of the Coumadin is then adjusted as necessary.
Following an episode of deep vein thrombosis it is wise to wear a firm below knee elastic stocking (30 - 40 mm compression) to control swelling. Failure to wear an elastic stocking can lead to chronic venous insufficiency and it's associated problems including pain, swelling, dermatitis, skin discoloration, and ulcerations.