Small red blood spots on the chest are usually considered to be caused by hemangioma, pressure purpura, and allergic purpura, and need to be judged according to the specific conditions of the patient. 1. Hemangioma: with the growth of age or long-term exposure to harmful substances, etc., will stimulate the patient’s vascular endothelial cells will produce abnormal proliferation, the surface of the skin will appear red pimples, small blood spots. 2. Pressure purpura: due to the chest suffered external impact, injury, etc., resulting in local small veins, arteries, capillaries rupture, accompanied by the leakage of extracellular fluid, there will be small red blood spots. 3. Anaphylactic purpura: If contact with their own allergic substances or the presence of bacterial, viral infections, etc., can induce anaphylactic purpura, manifested in the local skin symptoms of small blood spots. There may be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.