Hypercoagulable states are conditions that may lead to the abnormal development of blood clots. Blood clots can develop in either arteries or veins.

See also:

• Blood clots in the legs
• Deep venous thrombosis (DVT)
• Hepatic vein obstruction (Budd-Chiari syndrome)
• Mesenteric vein thrombosis
• Pulmonary embolus
• Stroke
• Stroke secondary to cardiogenic embolism

Thromboembolic states; Factor V Leiden; Prothrombin mutation 20210A

Hypercoagulable states fall into two groups:

• Inherited
• Acquired

Inherited means you are born with the tendency to form abnormal blood clots. Common inherited conditions that affect clotting are factor V Leiden and the prothrombin mutation 20210A. Rare inherited conditions include protein C, protein S, and antithrombin III deficiencies.

Acquired means you develop it later in life. Some medical situations can lead to the formation of abnormal blood clots. These include cancer, recent surgery or trauma, obesity, liver or kidney disease, and use of certain medications.

Conditions that can lead to the formation of blood clots include prolonged bedrest, dehydration, poor positioning (such as crossing the legs), sitting for long periods (such as in a plane or car), and long-term use of an intravenous catheter.

In women, birth control pills or hormone replacement therapy increase the risk of blood clots, and the risk is greatly increased in those who also smoke. The time before, during, and after pregnancy also increase the risk of clots.

Bauer K. Hypercoagulable states. In: Hoffman R, Benz EJ, Shattil SS, et al. Hematology: Basic Principles and Practice. 4th ed. Orlando, Fl: Churchill Livingstone; 2005:chap 127.