Coagulation simply refers to the clotting of the blood, which is essential for stopping the bleeding when a person has suffered from a damage or injury to the blood vessels. Coagulation is a complex process that involves several steps. The initial step in coagulation is the constriction of the damaged blood vessel, such that the blood will move more slowly and result in less bleeding.
After that, the platelets will receive a signal instructing them to assemble in the area of injury and create a platelet plug. This platelet plug will then serve as a temporary type of coagulation that will stop the bleeding. In order to strengthen and keep the platelet plug in its proper place, different types of proteins will also move to the damaged area.
Finally, the process of coagulation concludes with the formation of a special protection for the platelet plug called fibrin mesh. This mesh is created by a protein called thrombin, and provides support by holding the platelets in place and maintaining the blood clot. As the wound becomes older, the fibrin mesh also strengthens to allow the wound to heal completely. Once the wound is already healed and the entire process of coagulation is done, the hardened scab that was formed will gradually fall off.
The presence of too many platelets or other types of proteins involved in coagulation can lead to the clotting of blood even if it is not needed. Sometimes, a stroke may occur when the arteries become narrowed and the platelets get stuck together, forming a clot. On the other hand, there are some people who do not possess or lack certain types of proteins that are essential for the body to carry out the process of coagulation. Furthermore, there is also a condition called thrombocytopenia, which is characterized by insufficient platelet count. This absence or lack of platelets or proteins can lead to loss of significant amounts of blood even from minor injuries.