Blood clot formation is the result of a series of chemical interactions in which platelets and proteins in plasma work together to stop bleeding, according to the American Society of Hematology. Platelets form a plug to stop external bleeding, and clotting factors seal the inside of the wound, explains MedlinePlus.
Damaged blood vessels release triggers that signal platelets to start the clotting process, explains WebMD. The platelets adhere to the walls of the damaged vessels and release chemicals that attract even more platelets, states MedlinePlus. They change shape to form a plug that fills the broken part of the blood vessel and stops external bleeding.
In the next step, the clot grows as clotting factors signal each other and cause a rapid chain reaction, states WebMD. Dissolved substances in the blood form long strands of fibrin that tangle up with the platelets. This creates a net that traps more cells and platelets and completely seals the wound.
There are other clotting factors that stop the growth of the blood clot so that it does not spread further than it should, according to WebMD. After the damaged vessel heals, the fibrinolytic system dissolves the fibrin and restores the structure of the vessel, according to the Indiana Hemophilia and Thrombosis Center.
Normal blood clot formation involves the coordination of the three clotting processes: the procoagulant system, which promotes clotting; the anticoagulant system, which prevents clotting; and the fibrinolytic system, which breaks down the clot, explains the Indiana Hemophilia and Thrombosis Center. Individuals with clotting disorders have higher levels of procoagulants, lower levels of natural anticoagulants and a defective fibrinolytic system.