Fibrinolysis is a process that occurs inside the body to break down blood clots. This prevents blood clots from remaining in place and growing and allows the body to clear fragments of clots safely to avoid risks such as strokes and damage to the heart that can be caused by big floating clots. Primary fibrinolysis occurs naturally as the body clears clots that are no longer necessary once the underlying tissue is healed. Secondary fibrinolysis can be induced with medications or occur as the result of stress or disease.
When blood clots, it forms around a matrix of fibrin, a protein that is released during coagulation. The fibrin creates a framework for blood to clot around for the purpose of sealing a hole or covering a wound. Left in place, however, the clot could lead to the development of problems. In fibrinolysis, an enzyme called plasmin cuts through the fibrin to break the clot apart into smaller pieces that can be expelled by the body.
The precursor to plasmin, plasminogen, is produced in the liver. When blood starts to clot, plasminogen is locked inside the clot along with an activator that can turn the plasminogen into plasmin. As healing progresses, the activator is released to create plasmin to break up the clot. The body can also use inhibitors that interfere either with the action of the activator or the plasmin to slow fibrinolysis. This keeps the breakup of blood clots in balance.
The soluble pieces of the blood clot are moved through the liver. These components are broken down into parts for reuse or disposal. In people with clotting disorders or liver damage, it may be difficult for the body to process blood clots and complications can develop. These can include impairments in liver function that limit the ability to metabolize other chemical compounds that normally pass through the liver.
Sometimes, doctors may medicate patients with drugs that trigger fibrinolysis. This is done when a blood clot poses a threat to health, such as when there is a clot around the heart or near the brain. The drugs break up the clot so that it can be eliminated by the body. Medications to prevent fibrinolysis can also be prescribed for patients when their blood clots break up too quickly. Testing can be used to check for the levels of associated enzymes in the blood to learn more about why clots are forming or breaking up too quickly.