Deep Vein Thrombosis

Deep vein thrombosis, or DVT, is a blood clot that forms in a vein deep in the body. Blood clots occur when blood thickens and clumps together.

Most deep vein blood clots occur in the lower leg or thigh. They also can occur in other parts of the body.

A blood clot in a deep vein can break off and travel through the bloodstream. The loose clot is called an embolus. When the clot travels to the lungs and blocks blood flow, the condition is called pulmonary embolism, or PE.

PE is a very serious condition. It can damage the lungs and other organs in the body and cause death.

Blood clots in the thigh are more likely to break off and cause PE than blood clots in the lower leg or other parts of the body.

Blood clots also can form in the veins closer to the skin's surface. However, these clots won't break off and cause PE.

Who is at risk for DVT?

Many factors increase your risk for deep vein thrombosis (DVT). They include:

• A history of DVT.
• Disorders or factors that make your blood thicker or more likely to clot than normal. Certain inherited blood disorders (such as factor V Leiden) will do this. This also is true of treatment with hormone replacement therapy or using birth control pills.
• Injury to a deep vein from surgery, a broken bone, or other trauma.
• Slow blood flow in a deep vein from lack of movement. This may occur after surgery, if you're ill and in bed for a long time, or if you're traveling for a long time.
• Pregnancy and the first 6 weeks after giving birth.
• Recent or ongoing treatment for cancer.
• A central venous catheter. This is a tube placed in vein to allow easy access to the bloodstream for medical treatment.
• Being older than 60 (although DVT can occur in any age group).
• Being overweight or obese.

Your risk for DVT increases if you have more than one of the risk factors listed above.

Prevention

You can take steps to prevent deep vein thrombosis (DVT).

If you're at risk for DVT or pulmonary embolism (PE), you can help prevent the condition by:

• Seeing your doctor for regular checkups.
• Taking all medicines your doctor prescribes.
• Getting out of bed and moving around as soon as possible after surgery or illness. This lowers your chance of developing a blood clot.
• Exercising your lower leg muscles during long trips. This helps prevent a blood clot from forming.

If you've had DVT or PE before, you can help prevent future blood clots by following the above steps and:

• Taking all medicines your doctor prescribes to prevent or treat blood clots
• Following up with your doctor for tests and treatment
• Using compression stockings as your doctor directs to prevent swelling in your legs from DVT

Travel tips

Your risk of developing DVT while traveling is small. The risk increases if the travel time is longer than 4 hours, or if you have other risk factors for DVT.

During long trips, it may help to:

• Walk up and down the aisles of the bus, train, or airplane. If traveling by car, stop about every hour and walk around.
• Move your legs and flex and stretch your feet to encourage blood flow in your calves.
• Wear loose and comfortable clothing.
• Drink plenty of fluids and avoid alcohol.

If you're at increased risk for DVT, your doctor may recommend wearing compression stockings during travel or taking a blood-thinning medicine before traveling.