The human circulatory system, including bleeding and clotting, is far more complex than most people realize.
"For humans to survive in the world, our blood has to be able to clot quickly, but we also need the blood to stay liquid enough," points out Brian Smith, MD, chair of Yale Medicine's Department of Lab Medicine. "Our bodies have a complicated, dynamic coagulation system that helps us reach the right balance. To be healthy, both the platelet and liquid parts of the system need to be functioning properly."
If there is a malfunction and a person bleeds spontaneously or more easily or profusely than is typical, several blood tests can be done to identify what's not working.