Gangrene refers to a group of acute purulent infectious diseases of the skin or internal organs. At present, the clinical term gangrene refers to external gangrene, which is mainly a purulent disease of the skin, i.e. skin boils and carbuncles, with the main symptoms of localized redness, swelling, heat and pain and fever. Boil refers to purulent inflammation of the deep part of the hair follicle and the surrounding tissues, and is most common in the head, neck and buttocks. In the initial stage, it appears as a follicular inflammatory papule with a distinct basal infiltration, and the inflammation may rapidly expand to the surrounding area, forming a hard nodule accompanied by redness, swelling, heat and pain, and then softening and fluctuating in the center after a few days, and a pus plug may appear at the tip. Boils are usually multiple, and if they are numerous and recurrent, they are called boils, and are most often seen in immunocompromised or neutrophilic dysfunction. Carbuncles are deep infections of the skin formed by the fusion of multiple adjacent hair follicles and perifollicular inflammation, and are most common on the back of the neck, thighs, and buttocks. It initially presents as a diffuse hard lump of inflammation that rapidly spreads to the periphery and deeper into the skin, and then suppurates, softens and necroticizes in the middle, and may appear as multiple pus plugs. Carbuncles may be accompanied by localized lymph node enlargement and fever and other symptoms of systemic toxicity. Boils and carbuncles should not be blindly squeezed and medicated to avoid serious consequences. It is recommended to carry out regular anti-infection treatment under the guidance of a doctor.