Small pinpoint red blood spots on the arm may be small subcutaneous bleeding spots, if there is no other abnormality, just pay attention to it. If it is caused by abnormal blood clotting, it may be purpura. In addition, vascular nevus can also appear pinpoint small red blood spots, need to be carefully identified, and then deal with. 1, subcutaneous small bleeding spots: small bleeding spots on the arm is relatively common, if there is no other abnormalities, the blood spot does not expand, check the coagulation function is not abnormal, observation can be done, no special treatment; 2, purpura: such as allergic purpura, thrombocytopenic purpura, etc., generally due to the blood platelet Decreased or abnormal function, lack of or abnormal function of coagulation factors, and abnormal blood vessels cause pinpoint bleeding spots under the skin, mainly manifesting as submucosal bleeding, making the skin or mucosa red or purple. It can be treated with glucocorticoids, gammaglobulin, immunosuppressants, coagulation factor preparations, etc.; 3. Vascular nevus: It can be divided into hemangioma and vascular malformation, which is caused by abnormal development of vascular structure or abnormal proliferation of vascular endothelial cells, etc., and manifests as dark red or burgundy pinpoint red dots. Vascular nevus is mainly treated by topical topical drugs and systemic drugs, and assisted by laser, freezing or local injection to relieve symptoms.