Blood clotting, also known as coagulation, is a vital process that helps stop bleeding when a blood vessel is injured. It occurs whenever there is damage to a blood vessel, from a small scratch to more serious injuries. Here is how blood clotting works:

• When a blood vessel is damaged, the muscles in the vessel wall contract to reduce blood flow and minimize bleeding.
• Platelets (specialized cell fragments in the blood) are attracted to the injury site. They stick to the exposed collagen beneath the vessel lining and to each other with the help of a protein called von Willebrand factor. This forms a temporary platelet plug within seconds.
• To strengthen the plug, clotting factors (specific proteins in the blood) act together to convert a blood protein called fibrinogen into fibrin.
• Fibrin threads weave over the platelet plug, forming a strong and stable clot that seals the wound and prevents further bleeding.
• The fibrin clot also serves as a scaffold for new tissue growth during healing.
• Once the injury heals, the clot is naturally dissolved by the body.

This process ensures that bleeding is controlled quickly and the blood vessel is repaired efficiently. However, abnormal clotting can lead to medical conditions such as deep vein thrombosis, pulmonary embolism, or heart attacks if clots form inappropriately inside blood vessels. In summary, blood clotting is the body's crucial defense mechanism to prevent excessive blood loss after injury by forming a strong blood clot made up of platelets and fibrin that seals and heals damaged blood vessels.