A thrombus, or blood clot, is the final product of the blood coagulation step in hemostasis.
Blood clotting is an important mechanism to help the body repair injured blood vessels.
Blood consists of: -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 -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.
Blood clots are healthy and lifesaving when they stop bleeding. However, blood clots can also form abnormally, causing a heart attack, stroke, or other serious medical problems.
Most heart attacks and strokes result from the sudden formation of a blood clot on a waxy cholesterol plaque inside an artery in the heart or brain. When the plaque ruptures suddenly, thrombogenic substances inside the plaque are exposed to blood, triggering the blood clotting process.