March is National Deep Vein Thrombosis (DVT) Awareness Month. DVT affects as many as 600,000 Americans each year and can be deadly. DVT occurs when a blood clot develops in a vein deep in the body. Deep veins are found within groups of muscles. These are different from the veins close to the skin, which are called superficial veins.
While these clots most often develop in the lower legs or thighs, they may appear in the upper body, such as the arms or other locations in the body. DVT is a risk after any major surgery, but patients who have surgery of the legs or hips are at greater risk.
DVT can pose a serious threat to health. Pieces of a clot can break off and travel through the bloodstream to the lungs. This is called a pulmonary embolism and can be fatal soon after it occurs. DVT can also block blood flow in the veins, causing the blood to pool. This can cause swelling, pain and permanent damage to the leg called post-thrombotic syndrome.
What causes DVT?
A blood clot will form when blood flow in the veins slows, there is damage to a vein or the blood is in a state that clots are more easily formed. There are several risk factors that can set the conditions for the formation of a blood clot and DVT. However, while these risk factors increase a person's risk, they do not necessarily cause the disease. Some people with one or more risk factors never develop the disease, while others develop the disease and have no known risk factors. Knowing your risk factors for any disease can help to guide you into the appropriate actions, including changing behaviors and being clinically monitored for the disease.
Risk factors related to or that may contribute to deep vein thrombosis and thrombophlebitis include, but are not limited to:
- An inherited tendency that increases risk for blood clots
- 60 or older
- Surgery, particularly surgery of the hip or leg, or abdominal surgery
- A long period of bed rest or sitting for a long time (for example, on an airplane or in a car)
- Birth control pills or hormones taken for symptoms of menopause
- Certain diseases and conditions, such as:
- Varicose veins
- Chronic atrial fibrillation
- Inflammatory bowel disease
- Lupus erythematosus, a disease of the immune system
- Heart failure
- Heart attack
- Arterial disease
- Spinal cord injury and resulting paralysis
- Previous blood clot (thrombosis)
- Intensive care treatment involving placement of a central venous catheter
- People with cancer receiving chemotherapy
Symptoms of DVT
You should contact your health care provider if you experience the following symptoms:
- Swelling in the leg
- Red, discolored, or white skin
- Rapid heart beat (tachycardia)
- Slight fever
- Warm skin
- More visible surface veins
- Dull ache, tightness, tenderness or pain in the leg (these symptoms may only occur while walking or standing)
Treatment and Prevention
Treatment can be successful for DVT to ensure that either the blood clot does not continue to grow, break free and travel through the veins to the lungs or new blood clots do not form. Medication therapies can help to achieve these goals by either reducing the growth of the clot or literally dissolving the clot over the course of a few days. A vena cava filter may be available as treatment for patients not able to take the medication or when blood thinners do not work. A vena cava filter essentially grabs and removes the clot.
To help prevent DVT, talk to your doctor about what you can do to reduce your risk, whether you are recovering from surgery or traveling. When you travel and must sit for longer than four hours, the National Heart, Lung and Blood Institute suggests you:
- Walk up and down the aisles (if traveling by plane or bus)
- Stop about every hour and walk a little (if traveling by car)
- While sitting, stretch your feet and move your legs
- Wear loose clothing
- Avoid alcohol
- Drink plenty of fluids
Other preventive measures may include:
- Getting up and moving as soon as possible after surgery or illness, as movement can help to prevent clots from forming by stimulating blood circulation.
- Wearing a pneumatic compression device, which looks like a special fitted sleeve, placed on the legs to help keep blood moving during some types of surgery.
- Elastic stockings to reduce swelling and promote circulation.