The appearance of bruises on the body of the elderly is considered to be related to trauma, thrombocytopenic purpura and aplastic anemia and other diseases. 1. Trauma: If the elderly body suffers from trauma, it may lead to the rupture of subcutaneous blood vessels, which will lead to the appearance of bruises on the skin. 2. Thrombocytopenic purpura: the pathogenesis of this disease is mostly related to primary diseases, heredity and immunity, etc. Petechiae will appear on the skin and mucous membranes of the patients, and some of the elderly patients may have bruises on their bodies. 3. Aplastic anemia: the cause of this disease may be genetic, radiation, viral infection and immune abnormalities and other factors, the patient’s skin will appear bleeding spots, ecchymosis and other symptoms. If older people suffer from this disease, their skin may appear bruising symptoms. There are many causes of bruising in the elderly, and it is recommended that patients go to a regular hospital to get a clear picture of the cause of the disease.