Deep vein thrombosis is a blood clot that forms in a vein deep in the body. Most deep vein clots occur in the lower leg or thigh. They also can occur in other parts of the body.
If a clot in a vein breaks off and travels through your bloodstream, it can lodge in your lung. This is called pulmonary embolism, which is a very serious condition that can cause death. Blood clots in the thigh are usually more likely to break off and cause pulmonary embolism than clots in the lower leg or other parts of the body.
A blood clot also can occur in veins that are close to the surface of the skin. This type of blood clot is called superficial venous thrombosis or phlebitis. Blood clots in superficial veins are not dangerous because they can’t travel to the lungs.
Only about half of the people with deep vein thrombosis have symptoms. The symptoms may include:
- Swollen area of the leg
- Pain or tenderness in the leg. The pain is usually in one leg and may be felt only when standing or walking.
- Increased warmth in the area of the leg that is swollen or in pain
- Red or discolored skin
Some people find out that they have deep vein thrombosis only after the clot has moved from the leg and traveled to the lung (pulmonary embolism). The symptoms may include:
- Chest pain when you take a deep breath
- Shortness of breath
Several types of medicine may be used to treat and/or prevent deep vein thrombosis:
- Anticoagulants to decrease your blood's ability to clot
- Thrombolytics to quickly dissolve a blood clot
- Thrombin inhibitors to interfere with the clotting process
Vena cava filters are used when you can’t take medicines to thin your blood, or when you are taking blood thinners but continue to develop clots anyway. The filter is inserted inside a large vein called the vena cava. The filter catches clots that break off in a vein before they move through the bloodstream to the lungs (pulmonary embolism). The filter doesn’t prevent new clots from developing.
Graduated compression stockings can reduce the chronic swelling that can occur after a blood clot has developed in a leg. These stockings are tight at the ankle and become looser as they go up the calf to the knee. This causes a gentle compression (or pressure) up the leg. The pressure keeps blood from pooling and clotting.