Blood clot

Blood clot facts

• Blood clots form when blood fails to circulate adequately.
• Arterial thrombi form when a plaque ruptures and promotes an acute clot formation.
• Venous thrombosis occurs when prolonged immobilization allows blood to pool in an extremity and then clot.
• The diagnosis is suggested by the history and physical examination and often confirmed with a radiologic test.
• Treatment may require surgery, anti-coagulation medications, or a combination of the two.
• Prevention of blood clots involves attention to the risk factors for vascular disease.
• Serious complications can arise from blood clots, and individuals should seek medical care if they believe a blood clot exists.

What are blood clots?

Blood clotting is an important mechanism to help the body repair injured blood vessels. Blood consists of:Blood is a liquid that flows within blood vessels. It is constantly in motion as the heart pumps blood through arteries to the different organs and cells of the body. The blood is returned back to the heart by the veins. Veins are squeezed when muscles in the body contract and push the blood back to the heart.

• red blood cells containing hemoglobin that carry oxygen to cells and remove carbon dioxide (the waste product of metabolism),
• white blood cells that fight infection,
• platelets that are part of the clotting process of the body, and
• blood plasma, which contains fluid, chemicals and proteins that are important for bodily functions.

Complex mechanisms exist in the bloodstream to form clots where they are needed. If the lining of the blood vessels becomes damaged, platelets are recruited to the injured area to form an initial plug. These activated platelets release chemicals that start the clotting cascade, using a series of clotting factors produced by the body. Ultimately, fibrin is formed, the protein that crosslinks with itself to form a mesh that makes up the final blood clot.

The medical term for a blood clot is a thrombus (plural= thrombi). When a thrombus is formed as part of a normal repair process of the body, there is little consequence. Unfortunately, there are times when a thrombus (blood clot) will form when it is not needed, and this can have potentially significant consequences.

Reviewed by Melissa Conrad Stöppler, MD on 2/4/2013