Red spots on the body due to low platelets are caused by bleeding from capillaries under the mucous membranes of the skin. Platelets are an important blood component involved in the hemostatic process of the body. The normal range of platelet count is 100~300*10^9/L. When the platelet count decreases, capillary hemorrhage under the skin mucous membrane may occur, which may be manifested as pinpoint red spots, petechiae or ecchymosis on the skin. Red spots on the body, i.e., skin and mucous membrane bleeding spots, are mostly seen in patients with platelet counts lower than 50*10^9/L. However, there are individual differences, and not all patients with platelet counts lower than 50*10^9/L will have skin and mucous membrane bleeding spots. The lower the platelet count, the more serious skin and mucous membrane bleeding manifestations. When the platelet count is lower than 20*10^9/L, the human body may experience serious bleeding manifestations such as spontaneous intracranial hemorrhage, black stools, bloody stools and hematuria. It is recommended that the patient go to the hematology department in time to improve the bone marrow puncture, platelet autoantibody six and other related examinations to clarify the cause of the disease, and then target the cause of the disease, and actively promote platelet therapy.