In normal human peripheral blood, the normal value of platelets is (100-300) × 10^ cells/L, which can fluctuate up and down in a small range.
When the body is injured and bleeding occurs, a large number of platelets quickly gather near the wound and then block the wound together to stop the bleeding, they gather in clusters on the wall of the broken blood vessel and then form a clot, and the flow of blood naturally stops when the broken blood vessel is blocked. The blood flow naturally stops when the broken vessel is blocked.
When the platelet count decreases to 100 x 10^ cells/L or less, it is called thrombocytopenia, perhaps due to impaired production or excessive consumption, and is seen in various hematologic disorders, rheumatoid immune system disorders, and so on. In short, there are many different causes of thrombocytopenia, such as hereditary, immune factors, radiotherapy, chemotherapy damage, and other diseases caused by various diseases that attack the bone marrow and lead to low hematopoiesis, all of which can affect the quality and quantity of platelets.
When platelets are depressed, there is a tendency for more bleeding to occur, which may range from skin petechiae, nose bleeds, and gum bleeds in mild cases to brain bleeds in severe cases, when the risk is greater.