There are many reasons for small red blood spots on the body, such as red nevus, allergic purpura, and blood diseases. 1. red nevus: red nevus is mainly due to degenerative changes in body functions, capillary expansion, especially in the elderly, usually without special treatment. 2. Henochromatosis purpura: Henochromatosis purpura is caused by blood vessel damage, which can result in small red blood spots on the body, usually occurring in the lower limbs and commonly seen in teenagers. 3. Blood diseases: leukemia, myelodysplastic syndromes, thrombocytopenic purpura, etc., can also lead to the phenomenon of red blood spots on the body, and may also show other symptoms, such as fever, general weakness. There are many reasons for the red blood spots on the body, it is recommended to go to the hospital as soon as possible after the symptoms appear, follow the doctor’s instructions to take standardized treatment, to clarify the specific factors, do not ignore the symptoms, take it lightly.