Subcutaneous bleeding with small red dots may be a symptomatic manifestation of certain diseases, such as idiopathic thrombocytopenic purpura, hemangioma, anaphylactic purpura, cirrhosis of the liver, and capillary dilatation. The details are as follows. 1. idiopathic thrombocytopenic purpura: extensive microvascular endothelial cell injury, vascular hemophilic factor cleaving enzyme deficiency, platelet thrombus formation in microvessels, platelet consumptive reduction, secondary hemorrhage, and small red dots visible under the skin. 2. Hemangioma: abnormal proliferation of endothelial cells of blood vessels, often forming red plaques on the skin surface, with the development of the disease appears to break and bleed. 3. allergic purpura: under the action of various stimulating factors, a large number of inflammatory factors such as IgA, IgE, etc. are produced, triggering an abnormal immune response and leading to systemic vasculitis, which is mainly manifested as skin purpura, with deep red color. 4. Cirrhosis: the inactivation of estrogen by the liver is reduced, and estrogen can expand the small arteries in the skin, forming spider nevi. 5. Capillary dilatation: related to genetic factors, capillary dilatation of the skin surface, forming erythema. If there are small red spots of bleeding under the skin, you should go to the hospital in time, clarify the cause of the disease, and follow the doctor’s instructions for treatment.