A fire boil, or boil, on the back may be related to poor personal hygiene, damaged skin barrier, and low immunity. 1. Poor personal hygiene: If you often do not pay attention to personal hygiene, it will increase the probability of bacteria attacking the hair follicles and sebaceous glands. 2. Damaged skin barrier: If you suffer from eczema, acne and other skin diseases, the skin barrier can be damaged, making you susceptible to infection by bacteria and other pathogens and the occurrence of boils. 3. Low immunity: Diseases such as diabetes and anemia can lower the body’s immunity and make it more susceptible to bacterial infections. It is recommended that people with a boil on their back go to the hospital in time to get a clear diagnosis and standardized treatment under the guidance of a doctor to avoid delaying their condition.