The cause of chloasma is not clear, and it may be related to genetic susceptibility, ultraviolet radiation, changes in the level of sex hormones, and so on. Melasma is a yellowish-brown pigmentation spot on the face, mostly seen in young and middle-aged women, often symmetrically distributed. Clinical causes are related to heredity and have genetic susceptibility. Melasma has a certain genetic predisposition. In addition, ultraviolet radiation is also an important reason for the appearance and aggravation of melasma. In addition, changes in sex hormone levels can also cause melasma, and abnormalities in estrogen and progesterone are the main causes. At present, clinical treatment for melasma is mainly to make the color spots become lighter or return to normal, and the area of the spots is reduced or disappeared, and there are many kinds of clinical treatments. After the appearance of melasma, it is strictly forbidden to use drugs indiscriminately, and it is recommended to consult the dermatology department of the hospital.