1. Attention should be paid to avoiding light: ultraviolet radiation in the sun will induce chloasma or make chloasma aggravate. Therefore, we should pay attention to avoid strong sunlight, wear hats when we go out, and it is better to develop the good habit of playing umbrella when we go out. 2.Use sunscreen externally: It is necessary to prevent both medium-wave and long-wave ultraviolet rays, and sunscreen with high SPF value is optional in summer. 3. Be careful with cosmetics: Many melasma patients have a history of using poor-quality, expired and irritating cosmetics externally. Patients who have already suffered from melasma should be cautious in using cosmetics and should not apply cosmetics thickly to cover up melasma, which will aggravate melasma. You can use Bettysja day cream externally for both skin care and sun protection. Many patients suffering from melasma are eager to seek treatment and want to try it when they see the advertisement and go to find it when they hear the news, and change cosmetics frequently. In fact, they treat their face as a “testing ground”. This not only aggravates chloasma, but also adds new skin diseases. 4. Be careful with chemical drugs: sleeping pills and certain antibacterial agents can induce chloasma; the main ingredients of contraceptives are estrogen and progesterone, which can induce chloasma when progesterone increases in the body. 5. Internal and external treatment: Melasma caused by liver disease, kidney disease, blood disease, malnutrition or endocrine dysfunction, such as ovarian tumor, uterine fibroids, menstrual disorders, etc. should be treated promptly according to the causes. 6.In addition, sufficient sleep, pleasant emotions, less smoking and less alcohol.