Question

why bleeding time is less than clotting time

Answer 1

Hemostasis occurs in a sequence:
 1. Vasoconstriction
 2. Formation of platelet plug
 3. Formaion of clot

Bleeding time is the time from the onset of bleeding till the stoppage of bleeding i.e. temporary hemoststic plug formation (platelet plug). Clotting time is the time from the onset of bleeding till the clot formation (i.e. definitive hemostatic plug).

Hence, clotting time is longer then bleeding time.

Comments

thank you doctor

Answer 2

Bleeding time is a measure of platelet function whereas coagulation time/clotting time is a measure of the clotting factors. They're different components of the blood which we need for effective hemostatis.