A mole is a pigmentation that appears on the surface of the body, usually black or brown, but can also be blue, red or other colors. Most moles are congenital, i.e. they appear at birth, or they can grow out later. A normal person usually has 10 to 20 moles, and people with lighter skin color are more likely to have moles. Normally, moles do not pose a threat to one’s health, but as a kind of tumor, pigmented moles also have the risk of malignant transformation, so the health problems of pigmented moles on the body cannot be ignored. Malignant transformation of benign pigmented nevi is usually caused by chronic irritation, repeated rubbing and scratching, improper excavation and drug erosion. Therefore, moles on the body surface should avoid repeated rubbing and should be treated scientifically in a regular hospital, not in a street store or beauty salon. If the following conditions occur, it indicates that the pigmented mole may become malignant: 1. the surface of the mole breaks down and bleeds; 2. the area of the mole suddenly expands within a short period of time; 3. the mole appears painful and itchy and other abnormal sensations. Once the above situation occurs, you need to go to hospital immediately for treatment, removal of the lesion and pathological examination to clarify the exact nature of the tumor. Although there are clinical manifestations of nevus malignancy, the best treatment is to be proactive and carry out radical treatment before malignancy occurs. Since chronic irritation is a predisposing factor for malignant nevi, it is medically recommended that some specific nevi be removed prophylactically before lesions occur. Moles located in friction-prone areas of the body, such as the face, fingers, soles of the feet, lips, etc.; moles that are large and protrude from the body; moles that are large in size and affect aesthetics.