It is normal for normal people to bleed after skin and tissue damage, and damage to blood vessels. If bleeding occurs, the following conditions may occur: 1. Abnormalities in function. There may be functional abnormalities of the vascular structure, such as hereditary capillary dilation and vascular hemophilia. Also, it can be secondary to infections, chemicals, and the effects of drugs and certain metabolisms on the blood vessels. Also, like allergic purpura, mechanical irritation, or senile purpura, can cause abnormalities in vascular structure and lead to excessive blood flow.2. Abnormalities in platelet count or function, including primary thrombocytopenia, leukemia, functional anemia, drugs, infection, and hypersplenism, can cause a decrease in the number of platelets. Also, things like platelet incompetence, secondary medications and liver damage can affect platelet function and lead to abnormal coagulation.3. Abnormalities in coagulation factors, including hereditary hemophilia, secondary vitamin K deficiency, and severe liver disease.4. It is possible that the patient has taken oral anticoagulant substances such as warfarin. If there is significant bleeding, there may be a problem in the coagulation function or coagulation mechanism, and it is necessary to go to the hospital for examination and treatment after clarifying the cause.