Black flesh bumps that look like moles may be nevi or melanoma. Nevus melanosus is benign and is caused by the influence of hereditary factors, stimulation by sunlight exposure, and age-related degeneration of the stratum corneum. It is a benign growth. Melanoma generally does not need to be treated and is harmless to the body, and if it affects the aesthetics, you can choose laser excision. Melanoma is malignant on the basis of benign nevus, mostly due to long-term external stimulation or ultraviolet irradiation, which makes the original nevus increase in size, bulge, change in shape, and ulcer or inflammation, and then you have to choose surgical excision, and after excision, you have to carry out certain chemotherapy. Usually, we should pay attention to the process of changes of nevus and melanoma, if there are obvious changes in a short period of time, we should go to the hospital in time to do pathological examination.