The common causes of red blood spots on the body include allergic purpura, insect bite dermatitis and cherry angioma. 1. Anaphylactic purpura: the cause of this disease is unknown, may be related to infection, allergy, drugs, genetics and other factors, manifested in the skin with purplish-red maculopapular rash and other symptoms. 2. Insect bite dermatitis: this disease is caused by mites, mosquitoes, midges, bedbugs, fleas, ticks and other insect bites or poisonous sap irritation. It manifests as bleeding spots, papules, macules, scratches, itching and other symptoms on the skin. 3. Cherry angioma: the cause of this disease is currently unknown, may be related to skin aging, often manifested as red papules on the skin, nodules, etc., the number varies, and can be distributed in all parts of the body. It is recommended that patients go to the dermatology department of regular hospitals in time, follow the doctor’s instructions to clarify the cause of the disease, and timely treatment to avoid delaying the condition.