Sudden growth of moles on the chin may be caused by sebaceous nevus, pigmented nevus and other diseases, but there are also other facial swellings that can be mistaken for moles. 1. Sebaceous nevus: The occurrence of sebaceous nevus is related to the abnormal development of epidermis, dermis and skin appendages. Commonly found in scalp and face, the damage is round, ovoid, banded, and the color can be changed from light yellow to brown, light brown to brown, so the patients will have the situation of sudden growth of nevus on chin. 2. Pigmented nevus: this disease is a benign skin tumor of melanocyte origin, which may be induced by ultraviolet irradiation, trauma, hormone level change, immunosuppression and other factors, and may be manifested as sudden growth of nevus on chin. 3. Other: Sudden growth of moles on the chin may also be seborrheic keratosis, common warts, fibroma, etc., which need to seek professional medical treatment to make a clear diagnosis. It is recommended that patients with sudden growth of moles on the chin go to the hospital to complete the relevant examinations to clarify the specific cause.