If one kidney is removed and the other kidney functions normally, then there is not much harm to the body. If both kidneys are removed, then the patient will enter the stage of uremia. The main function of kidney is like a filter, which can filter toxins and water, thus maintaining the stability of the internal environment of the body. If a patient has a complete loss of function of this side of the kidney due to some reasons, such as a tumor on one side of the kidney or a long-term kidney stone, then a nephrectomy can be given. After the removal, if the other kidney is normal, there is no harm to the body, and the kidney on the healthy side will be able to fully detoxify and drain to maintain the stability of the internal environment of the body. If the patient has nephrectomy on both sides for some reasons, the patient will have no more organs to detoxify and drain, and will enter the stage of uremia, which will require long-term hemodialysis treatment, otherwise it will easily cause serious heart failure, cerebral edema, hyperkalemia and lead to the death of the patient.