Hyperpigmentation is generally able to subside on its own, because most hyperpigmentation from a clinical point of view belongs to post-inflammatory hyperpigmentation. The general cause of the formation of post-inflammatory hyperpigmentation is mainly due to early inflammation of the skin, which stimulates the melanocytes in the basal layer of the epidermis, producing abnormal secretion of melanocytes, or producing melanin, which is the pigmentation after the inflammation subsides. But over time, the melanin will gradually be metabolized and the hyperpigmentation will gradually fade away. There may be other causes of hyperpigmentation, such as melanosis, which are difficult to subside.