There are many reasons for the growth of moles, and generally speaking, various factors, such as endocrine disorders, local skin infections, irregular diet and rest, genetic factors or systemic immune diseases, may cause the increase of melanocytes or dysfunction in the skin. Usually benign moles are common, but malignant changes may occur, such as asymmetrical appearance, uneven pigmentation, irregular edges, unclear boundaries or large diameters of moles, etc. It is necessary to consider the possibility of malignant changes. If this happens, it is recommended to consult a dermatologist for local pathological biopsy to clarify the cause and lead to treatment. In addition, it is recommended to pay attention to skin cleanliness and hygiene in life to prevent skin breakage or to find abnormalities, and early treatment and therapy are recommended to prevent malignant changes, etc.