Black folds around the anus may be caused by hyperpigmentation, hemorrhoids, anal eczema and other factors. 1. Hyperpigmentation: with age, sexual life and other influences, the body’s sex hormone level rises, may cause the skin around the anus to produce hyperpigmentation, in addition, defecation stimulation, intimate clothing long-term friction, etc., will also be formed in the case of hyperpigmentation, this kind of belongs to the normal physiological phenomenon, usually do not need to intervene in the treatment, pay attention to the observation can be. 2. Hemorrhoids: the occurrence of hemorrhoids is usually associated with peripheral venous reflux obstruction, which may lead to black folds around the anus, and may also be accompanied by anal pain, itching, defecation difficulties, defecation with blood and other uncomfortable symptoms. 3. Anal eczema: anal eczema may also cause skin pigmentation around the anus, manifested as black, accompanied by obvious itching, blisters, redness and other changes. In addition, anal cleaning is not in place, pigmented nevus, melanoma and other factors may also cause black folds around the anus, it is recommended that the patient consult a doctor in a timely manner for examination, to clarify the cause of the disease for targeted treatment.