What is the first stage of hemostasis?

The first stage of hemostasis is the vascular phase. This phase begins immediately after a blood vessel is damaged, leading to the constriction of the vessel walls (vascular spasm) in response to injury. This reaction is essential because it reduces blood flow to the affected area and minimizes blood loss. During this initial stage, the endothelial cells of the blood vessels become sticky, which aids in the aggregation of platelets that will occur in the subsequent platelet phase.

Understanding the vascular phase is crucial for phlebotomists and healthcare professionals, as it sets the stage for the body's natural healing processes and is integral for effective blood coagulation. The other phases, such as the platelet and coagulation phases, follow the vascular response and are important but occur after the initial vascular spasm has taken place.