Carbuncles and gangrene (which are poisonous sores, acute suppurative diseases occurring on the body surface, limbs, and internal organs) are difficult to ulcerate means that carbuncles and gangrene are difficult to ulcerate after they become pus, and the pus can’t be completely discharged in the affected area. Carbuncles and gangrene are acute suppurative diseases that mostly occur on the surface of the body, internal organs, limbs and other parts of the body. However, carbuncle and gangrene have some difference, carbuncle occurs in muscle, the surface is red and swollen, the pus is high, so it is mostly belongs to Yang evidence. Gangrene mostly occurs on the bone, the surface is relatively flat, the color is dark, mostly belongs to the yin evidence. When carbuncle and gangrene pus is not yet finished, some drugs should be used to dissolve the pus, and if the pus has been finished, the pus should be drained out. If the carbuncle and gangrene are difficult to be ulcerated, when the pus has already been formed, but it is difficult to be discharged, then some pus-eliminating medicines are needed to discharge all the pus smoothly, which will be conducive to the healing of the wound. When the patient has carbuncle and gangrene hard to be ulcerated, he should go to the regular hospital immediately, and must not delay the condition, so as not to cause adverse consequences.