There are many different kinds of platelet function disorders. In platelet function disorders, a person's blood platelets do not work properly. The result is that blood does not clot the way it should.
Blood is carried throughout the body within a network of blood vessels.
When tissues are injured, damage to a blood vessel may result in leakage of blood through holes in the vessel wall. The vessels can break near the surface, as in a cut. Or they can break deep inside the body, making a bruise or an internal hemorrhage. Platelets are small cells circulating in the blood. There are 150 to 400 billion platelets in a normal litre of blood.