Frequently, it is discovered that a kidney is non functioning, or at least functioning below maximum efficiency. If the damage has only been done to one kidney, then the other kidney is likely to take over, and it may be some time before the damage is discovered, but if both kidneys are affected, or if there is only one kidney present, then renal failure may well develop, and this is a situation that is usually handled by a non surgical kidney specialist, known as a nephrologist. If it is just one kidney that is damaged, perhaps by a long standing stone problem, then the surgeon's duty is to make sure that the remaining kidney is working well, and then deciding whether the "bad" kidney should be removed or not. These days, removal of a small shrunken kidney can often be successfully carried out using a laparoscopic approach, which has a smaller impact on the patient, and a quicker recovery time, but your surgeon will be able to advise whether this would be appropriate in your own case.