Under normal conditions, kidney function remains normal, although sometimes slower than in a younger person. However, decreased efficiency occurs when the kidneys are under an increased workload. Illness, medications, and other conditions can increase kidney workload. The changes in the kidneys may affect an elderly person's ability to concentrate urine. The response to changes in fluids and electrolytes taken in is slowed.
Dehydration occurs more readily.
Bladder infections and other urinary tract infections are more common in the elderly. In part, this is related to incomplete emptying. It is also related to changes in the chemical balance of the urinary membranes. In both men and women, urinary changes are closely related to changes in the reproductive system.