Sudden aggravation of chloasma may be related to bad mood, lack of sleep, excessive sun exposure and so on. 1. Adverse emotion: long-term depression, anxiety and other adverse emotions may lead to the aggravation of melasma. Of course, there will be a slow accumulation process before the sudden aggravation, and emotion is one of the important factors. 2. Lack of sleep: Staying up late and irregular work and rest will aggravate anxiety and depression, and also slow down the metabolism of the body, leading to the aggravation of melasma. 3. Excessive sun exposure: prolonged exposure to ultraviolet rays without strict sun protection measures will increase the production of melanin, which may also lead to the sudden aggravation of melasma. When chloasma suddenly worsens, you should consult the doctor in time and have targeted treatment or therapy under the doctor’s guidance.