Deep Vein Thrombosis (Blood Clot in the Leg, DVT)
Deep vein thrombosis (DVT) is a blood clot in one of the major deep veins, usually of the lower legs, thighs, or pelvis. A clot blocks blood circulation through these veins, which carries blood from the lower body back to the heart. The blockage can cause pain, swelling, or warmth in the leg. Blood clots in the veins can cause inflammation called thrombophlebitis. If the clot breaks loose and travels through the bloodstream, it can block a blood vessel in the lungs. Called pulmonary embolism, this can lead to severe trouble breathing and even death.
In the U.S., between 300,000 and 600,000 people per year get
deep vein thrombosis. About 100,000 people die each year from pulmonary embolism.
Deep Vein Thrombosis Causes
Three things can cause a clot to form inside a blood vessel:
Damage to the inside of a blood vessel
Changes in normal blood flow
Hypercoagulability, a state in which the blood is more likely than usual to clot
Anything that contributes to one or more of these three things can cause deep vein thrombosis. The common risk factors are:
Sitting for a long time, such as during a long plane or car ride
bed rest or immobility, such as after an injury or while ill (for instance, after a stroke) Recent surgery, particularly orthopedic, gynecologic, or heart surgery
Recent injury to the lower body, such as
fractures of the bones of the hip, thigh, or lower leg
Heart attack or heart failure Recent
childbirth Being at very high altitude, greater than 14,000 feet
Estrogen replacement therapy or birth control pills
Rare, inherited blood-clotting problems
Disseminated intravascular coagulation (DIC), a condition in which blood clotting occurs inappropriately, usually caused by overwhelming infection or organ failure
Certain heart or respiratory conditions
If a person has one deep vein thrombosis, they are more likely to have a second deep vein thrombosis.
Deep Vein Thrombosis Symptoms
Symptoms happen in the leg when a clot blocks blood flow and causes inflammation. Symptoms may include the following:
Warmth to the touch
leg pain when bending the ankle up towards the shin Leg
cramps, especially at night Bluish or whitish
About 50% of people with deep vein thrombosis do not have symptoms.