The appearance of blisters during cupping is a normal reaction, indicating that the dampness in the body is more serious. If there is blood inside the blisters, it should be considered a sign of heat toxicity. Different colors of blisters represent different diseases, for example, purple-black is insufficient blood supply and has accumulated cold. Purple if accompanied by black spots, consider it to be a lack of Qi and blood circulation. If there are purple spots and there are shades of lumps is rheumatism. Bright red and brighter in color with localized heat, consider Yang syndrome, heat syndrome, actual syndrome, incandescence of heat toxins, Yin deficiency of the body, and fire. If it is red and dark, consider it to be sticky blood, high blood lipid, and insufficient blood supply. If the petechiae or blood blisters are greyer and lighter in color, consider deficiency cold and dampness. If the skin is slightly itchy, consider wind and dampness. Blisters, edema and dampness are cold and more severe dampness. Those with water droplets in the jar should be considered to be heavy with cold and dampness. A purplish red or dark red color is a yin syndrome, cold syndrome, etc. This condition usually returns to its original state quickly, indicating that healing is relatively fast.