Reviewed by Brian R. Robinson, MD
A deep vein thrombosis (DVT) is a blood clot found in a vein that accompanies an artery, known as a deep vein. DVT usually affects veins in the lower leg and thigh, which comprise of the largest, most central veins in the body. When a large clot (or thrombus) forms, it may interfere with circulation or break off and embolize, or move though the blood stream where it can and can lodge in any area, causing severe damage to the part of the body where it settles (for example, in the lung as a pulmonary embolism, or PE). DVT occurs in approximately 2 out of 1,000 people, most of who are over age 60. DVT causes problems both in the deep veins where it originates and due to embolization in the lungs and other locations in the body.
Risk factors for DVT include:
• Prolonged bed rest or immobilization
• Recent surgery, fracture, or trauma
• Recent childbirth
• Use of medications such as birth control pills or estrogen