The causes of subcutaneous bleeding in children are numerous. Normal subcutaneous bleeding in children is usually small and absorbs on its own within a short period of time, whereas disease factors such as idiopathic thrombocytopenic purpura, aplastic anaemia, acute leukaemia, hereditary haemorrhagic capillary dilation, allergic purpura, coagulation factor deficiency, etc. are all causes of subcutaneous bleeding in children. Therefore, in children with subcutaneous bleeding, if it is not due to trauma and has not been absorbed for a long time, it should be considered as a disease and should be treated promptly at a hospital.