DEEP VEIN THROMBOSIS
Venous thrombosis is a condition in which a blood clot (thrombus) forms in a vein. This clot can limit blood flow through the vein, causing swelling and pain. Most commonly, venous thrombosis occurs in the "deep veins" in the legs, thighs, or pelvis. This is called a deep vein thrombosis, or DVT.
Venous thrombosis can form anywhere in the venous system. However, DVT is the most common type of venous thrombosis. If a part or all of the blood clot in the vein breaks off from the site where it was created, it can travel through the venous system; this is called an embolus. If the embolus lodges in the lung, it is called pulmonary embolism (PE), a serious condition that leads to over 50,000 deaths a year in the United States. In most cases, PE is caused by a DVT when part of a blood clot breaks off and lodges in the lung. The term "venous thromboembolism" is sometimes used when discussing both DVT and PE.
Some medical conditions and medications increase a person's risk of developing a blood clot. These include:
- Pregnancy
- Obesity
- Smoking
- Heart failure
- Previous DVT or PE
- Increased age
- Cancer — Some cancers increase substances in the blood that cause blood to clot
- Kidney problems, such as nephrotic syndrome
- Certain medications (eg, birth control pills, hormone replacement therapy, erythropoietin, tamoxifen, thalidomide). The risk of a blood clot is further increased in people who use one of these medications and smokes or is overweight.
SIGNS AND SYMPTOMS — The signs and symptoms of DVT may be caused by the clot, or may be related to another condition. Imaging studies are needed to determine if a clot is present. Classic symptoms of DVT include swelling, pain, warmth, and redness in the involved leg.
(Source: UpToDate, review article by Gregory YH Lip, MD, FRCPE, FESC, FACC, Graham F Pineo, MD Kenneth A Bauer, MD, 2007)
See Also:
DVT Treatment
