It is not possible to identify physical diseases only by the color after cupping, but it can reflect some physical conditions, and identify physical diseases by looking, smelling, questioning and cutting, and comprehensive analysis. 1. Purple-black: The color after cupping is purple-black, which may be caused by stagnation of qi and blood stasis (due to blood stasis caused by the lack of qi), often accompanied by local distension, stuffiness, plumpness, pain, sometimes light and sometimes heavy, plumpness under the dermatomes (lumps), pain and refusal to be pressed. 2. Greenish-gray: greenish-gray color after cupping, may be caused by cold and dampness, often accompanied by cold fear of cold limbs (fear of cold, cold limbs), abdominal distension, diarrhea or swelling. If there is any discomfort, it is recommended to consult a doctor in time. If cupping treatment is needed, it is recommended to go to a professional medical institution.