The bladder is a small bump on the consideration of common warts, molluscum contagiosum, sebaceous cysts and so on. 1. common warts: the occurrence of common warts and human papilloma virus infection, human infection with this virus, the virus will induce epithelial tissue proliferation, so that the epithelium thickening and keratinization of the papillary tumor. 2. Molluscum contagiosum: also known as dermatofibroma, it is a kind of benign skin tumor, which is more common in middle-aged and old-aged people, the older the incidence rate is higher, and it is mainly manifested as a high-tip growth above the surface of the skin, and it may be filamentous, bulbous or pocket-shaped. 3. Sebaceous cysts: The occurrence of sebaceous cysts is related to the accumulation of sebum. Under normal circumstances, the sebaceous glands will secrete sebum through the ducts to the skin, but if the sebaceous glands are blocked, the sebum will gather to form cysts. Small bumps on the bladder may have other causes (such as dermatofibroma), it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.