The water inside a foot blister is a tissue exudate that results from a local inflammatory reaction due to a fungal infection. Usually the tissue exudate in the blisters is not fungal, so it is generally not infectious. Foot blisters are usually found between the toes, palms, toes and edges of the feet, and the lesions are initially pinpoint-sized deep blisters that may fuse into large multifocal blisters. The blister walls are removed to reveal a honeycomb base and a bright red vesicular surface that dries and absorbs and then becomes flaky and itchy. It is usually not recommended to pick the blister, if the blister is picked, it is easy to form an open wound, and if no attention is paid to disinfection, it is easy to develop a secondary bacterial infection. If the blisters are small, topical medications such as ketoconazole cream and miconazole nitrate cream can be applied under the guidance of a doctor to promote their self-absorption. If large blisters appear and affect walking, prompt medical attention is required and the doctor will use a syringe to aspirate the blister under strict sterilization to shrink it. Patients are advised to actively seek medical consultation and treatment, and scratching is strictly prohibited to avoid rupture of blisters and formation of impregnated erosion type foot fungus, which adds complexity to the treatment. In daily life, you should pay attention to personal hygiene and not share shoes and socks, bath tubs and footbaths with others. Wearing breathable and comfortable shoes and socks and keeping the feet dry can effectively avoid the breeding of fungi and bacteria.