Nevus is known as pigmented nevus in medicine, belongs to one kind of mole, there are more types of nevus, its clinical manifestation is diversified, some types of nevus generally do not need special treatment, some nevus need physical therapy, surgical treatment and other treatments. 1. Clinical symptoms: Nevus pigmentosus can occur in any part of the body, it is a patchy rash or papule with clear boundary, usually in yellowish-brown or black color; nevus pigmentosus, nevus pigmentosus, nevus anemicus, nevus of Ota, nevus of sebaceous glands and so on, its preferred parts are different, such as head, face, limbs, trunk and so on, and the characteristics of lesions are either white spots, or patches or plaques in brown, black or skin color. 2. Treatment: pigmented nevi generally do not need treatment and can be removed by laser or surgical excision when they affect the aesthetics. Some types of moles don’t need treatment, but when they seriously affect the patient’s appearance and physical and mental health, they need to be actively treated, such as nevus of Ota which affects the eyes, tympanic membrane and other functions can be treated with laser, and nevus of sebaceous glands which seriously affects the appearance, or has the tendency of cancerous transformation can be completely excised by surgery. There are many types of nevus, pigmented nevus belongs to one of them, generally do not need treatment, but when the nevus suddenly increases in size, turns black in color, and has symptoms such as vesicles, ulcers, bleeding, and pain on the surface, it is necessary to consult a doctor in time.