Office workers who work overtime are prone to low immunity. The first reason is that life is irregular, and there is no way to absorb food and nutrition according to three meals a day. Second, life is irregular, and there is no way to do physical exercise at a fixed time, which leads to a decline in physical function. The third is that the normal sleep time is disrupted, the body's biological clock is chaotic, and the body's immunity is reduced. Fourth, overtime will bring psychological and physical stress, and it will also lead to the decline of physical immunity.