Bruising on the body for no reason may be thrombocytopenia, coagulation dysfunction and other factors, the elderly is also seen in senile purpura and other factors. 1. Thrombocytopenia: when the patient’s body platelet reduction, it will lead to the patient’s hemostatic function has been weakened, some patients are prone to skin surface bruising. 2. Coagulation dysfunction: when coagulation dysfunction occurs, such as hemophilia and vitamin K deficiency, bleeding can occur in the skin and mucous membranes, and the patient can show up with bruises for no reason. 3. Elderly purpura: mainly due to aging and long-term exposure to sunlight, zinc deficiency and other factors. The sun-exposed areas may appear in varying sizes of petechiae and ecchymosis, often dark purple. Patients need to go to the hospital for relevant examinations, such as blood routine, etc., to avoid further development of the disease and delay the condition.