A bad kidney on one side may affect the other kidney. The main function of kidneys is to excrete the wastes produced by the body during metabolism and to maintain the balance and stability of the body’s internal environment. When one kidney breaks down, the other kidney has to take on the operation of both kidneys. A single kidney is under more pressure and is in a state of high filtration in the early stages, and the kidney may increase in size compensatorily. But a healthy kidney can usually support the body’s normal life. A necrotic kidney on one side may affect the surrounding organs and may lead to an infection in the other kidney. Therefore, removing the necrotic and shrunken kidney that has no function may be effective in avoiding infection of the other kidney. If the patient has one side of kidney necrosis, it is recommended to seek medical treatment in time.