Journal of Blood Disorders & Transfusion

Coagulation

Coagulation is a critical physiological process that prevents excessive bleeding when blood vessels are injured. It involves a complex cascade of events where blood transforms from a liquid to a gel, forming a clot. This process is essential for maintaining hemostasis, the body's ability to stop bleeding and repair damaged tissues.

The coagulation process begins when a blood vessel is damaged, triggering the exposure of collagen and tissue factor. Platelets adhere to the injury site, forming a temporary plug. Concurrently, the coagulation cascade activates, involving a series of enzymatic reactions that culminate in the conversion of fibrinogen to fibrin by the enzyme thrombin. Fibrin strands weave through the platelet plug, stabilizing the clot and creating a mesh that holds the wound edges together.

Coagulation is tightly regulated by various proteins and factors, including clotting factors, calcium ions, and vitamin K. Imbalances in this system can lead to disorders: excessive clotting, known as thrombosis, can cause conditions like deep vein thrombosis or stroke, while insufficient clotting, or hemorrhage, can lead to excessive bleeding.

Research in coagulation focuses on understanding these mechanisms and developing treatments for coagulation disorders. Anticoagulants, such as warfarin and heparin, are used to prevent clot formation in patients at risk of thrombosis, while clotting factor replacements are critical for treating hemophilia. Advances in this field continue to improve patient outcomes and safety in surgeries and trauma care.