Primary or secondary fibrinolysis

Blood clot formation

Blood clotting normally occurs when there is damage to a blood vessel. Platelets immediately begin to adhere to the cut edges of the vessel and release chemicals to attract even more platelets. A platelet plug is formed, and the external bleeding stops.Next, small molecules, called clotting factors, cause strands of blood-borne materials, called fibrin, to stick together and seal the inside of the wound. Eventually, the cut blood vessel heals and the blood clot dissolves after a few days.

Also known as: Fibrinolysis

Definition

Fibrinolysis is a normal body process that keeps naturally occurring blood clots from growing and causing problems.

Primary fibrinolysis refers to the normal breakdown of clots.

Secondary fibrinolysis is the breakdown of blood clots due to a medical disorder, medicine, or other cause.

Causes, incidence, and risk factors

Blood clots form on a protein called fibrin. The breakdown of fibrin (fibrinolysis) can increase under certain conditions, such as:

  • Bacterial infections
  • Intense exercise
  • Low blood sugar
  • Not enough oxygen to tissues

In some situations, doctors may wish to speed up the rate of fibrinolysis. For example, when an abnormal clot forms in the blood vessels of the heart and results in a heart attack, human-made fibrinolytic substances (such as tPA, streptokinase, or Retavase) may be given to break up the clot.

References

Schafer AI. Hemorrhagic disorders: Disseminated intravascular coagulation, liver failure, and vitamin K deficiency. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 181.

See also:

  • Disease

    Blood clots

    Thrombus

    Blood clots are clumps that occur when blood hardens from a liquid to a solid. A blood clot that forms inside a blood vessel or within the heart and stays there is called a thrombus. A thrombus that breaks loose and travels from one location in the body to another is called an embolus. The ...

Review date:
February 5, 2010
Reviewed by:
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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