Excessive blood clotting is a condition in which blood clots form too easily or don't dissolve properly.
Normally, blood clots form to seal small cuts or breaks on blood vessel walls and stop bleeding. Blood clots also can form due to slow blood flow in the blood vessels. For example, if a blood vessel narrows, blood flow may slow down as it moves through the vessel.
There are many causes of excessive blood clotting. The condition may be due to problems with the blood, blood vessel defects, or other factors. Regardless of the cause, problem blood clots can limit or block blood flow. This can damage the body's organs or even cause death.