Deep vein thrombosis is common, beware risk factors

Each year, 1 in every 1,000 people develops a deep vein thrombosis, or blood clot that forms in a deep vein.

March was Deep Vein Thrombosis Month, but awareness should be year-round as DVT can have serious complications — including death.


Your heart pumps blood into arteries, which then bring the blood to all parts of your body. Veins bring the blood back from the body to the heart. They start as tiny vessels, branching to become larger and larger as they return to the heart. Veins run next to arteries and are deep in your body. In your legs, they are deep in the muscle and close to the bones.


Most Deep Vein Thrombosis or DVTs occur in the lower leg, thigh or pelvis, although they can occur in other parts of the body. The clot might partially occlude the vein or plug the entire vein.


If the clot breaks off and travels, it is known as an embolus. The embolus will become lodged in the lungs; this is known as a Pulmonary Embolus or PE. If there are many embolic clots or the clot is large, pulmonary embolism can be fatal.

Therefore, DVT must be treated as a medical emergency. DVT can also lead to complications in the legs, referred to as post-thrombotic syndrome. The clot damages small valves in the veins, resulting in venous insufficiency. This condition causes blood to pool in the legs, which results in chronic leg swelling, leg pain, leg cramps, discoloration of the skin and, in severe cases, ulcers known as venous stasis ulcers.


There are circumstances that increase your risk for developing a DVT. The more of these conditions that you experience, the greater your risk; for example, the combination of obesity, smoking, birth control pills and recent surgery can be a serious risk for DVT.

In 25 percent to 50 percent of people with DVT, however, there is no cause or risk present. This is known as “idiopathic” DVT.

■ Inactivity: The calf muscle in your leg acts like the heart. It helps keep blood moving up the leg. With inactivity, blood tends to accumulate in the legs and slow-moving blood can clot. Sixty percent of all DVTs occur with immobilization.

■ Advanced age: The chance of having a DVT increases dramatically after the age of 60. One out of every 300 people older than 70 will develop a DVT.

■ Injury or surgery: Damage to the veins and can slow the flow of blood. Twenty-five percent of all DVTs occurred after surgery.

■ Clotting disorders: Inherited clotting conditions can significantly increase your risk for DVT. Talk to your doctor if young or middle-age family members have had DVT.

■ Hormone replacement/oral contraceptives: There is increased risk with estrogen hormones, such as oral contraceptives or hormone replacement therapy (HRT).

■ Pregnancy: There is higher risk of DVT during pregnancy because of high estrogen levels and the uterus pressing on a woman’s pelvic veins. A pregnant woman’s risk continues for weeks after delivery.

■ Malignancy: Twenty percent of all DVTs occur in patients with cancer.

■ Poorly functioning veins: Leg vein problems, such as varicose veins, lead to pooling of blood in the legs and increase the chance of a clot.

■ Heart failure: In heart failure, the heart is not moving blood out of the legs effectively, which might allow a clot to form.

■ Obesity: Obese people have more pressure on their pelvic and leg veins.

■ Tobacco: Smokers are more likely to develop DVT.

■ Previous DVT: If you have had a DVT, you have a 10 percent chance of another DVT within the first year.


Fifty percent of people with DVT may not have obvious symptoms. The most common symptom is leg pain and tenderness in the calf. The area may look purple or red and feel warm to the touch. There may be fullness of the veins under the skin and swelling. These symptoms may appear suddenly or develop over a short period. Usually only one leg is affected.

If the clot breaks loose to become a PE, you may experience chest pain, often worse with breathing and coughing, shortness of breath and a rapid heart rate. There may be a feeling of apprehension, sweating, or fainting. These symptoms are not specific for PE and can occur with other medical conditions, such as pneumonia or a heart attack. Regardless, these are always critical symptoms that demand immediate medical attention. Call 911 immediately.


It is often difficult to diagnose a DVT from only your signs and symptoms. Your doctor might order an ultrasound of your leg to look at the veins. If a PE is suspected, you will need a special X-ray of your chest called computed tomography (CT) scan.


Both DVT and PE are treated with blood-thinning medications called anticoagulants. These may be given as pills, shots, or as an intravenous infusion. These medications decrease your blood’s ability to clot. This is necessary to stop the clots from getting bigger, help prevent PE and to help prevent post-thrombotic syndrome. These medications are also often used in hospitalized patients to prevent DVT. They do not, however, dissolve the clots that have already formed. The body’s natural systems may slowly eliminate these. Most people need to take blood thinners for at least three to six months, but some may need them longer.


If you have been diagnosed with a DVT, prevent further clots by:

■ Taking your blood thinning medications as prescribed by your doctor.

■ Keeping your follow-up appointments with your doctor and the laboratory so your response to the medications can be evaluated.

You may prevent DVT by:

■ Avoiding long periods of inactivity. Exercise your lower leg muscles by flexing your feet if sitting still for a long period. Stand up and walk at least every half-hour if you are on a long flight or get out of the car every hour.

■ Getting out of bed as soon as possible after surgery or an illness.

■ Elevating your legs if you are sitting for a long period.

■ Staying well hydrated. Caffeine and alcohol will dehydrate you.

■ Wearing compression hose if you have varicose veins or will be inactive from illness or travel.

■ Losing weight and stopping smoking; your healthcare provider can guide you to a program that is right for you.