— Dr. J, Texas An enlarged nonfunctioning kidney does not necessarily need to be removed, unless it contains stones, a tumor, or an infection that could be dangerous if left inside the body. Very rarely does a nonfunctioning kidney cause damage to the opposite, normal kidney. However, if the kidney contains stones and infection, it could become the source of more widespread infection, leading to general health problems. Some obstructive kidneys produce hormones, which can increase blood pressure and, in turn, affect the opposite, healthy kidney. However, this is very rare. It is important to know what the cause of the obstruction is. If the enlarged, obstructed kidney is the result of a congenital (present from birth) obstruction of the urinary tract, the kidney can often be left in place. If, however, there is suspicion of a malignant tumor, either in the kidney itself or in the outflow tract (ureter), then obviously further diagnostic testing is indicated, and it may be more prudent to remove the kidney. Learn more in the Everyday Health Kidney Cancer Center.