Medullary sponge kidney is usually caused by a nongenetic abnormality that occurs during development of the fetus. Much less often, the abnormality is hereditary. Medullary sponge kidney causes no symptoms most of the time, but a person with the disorder is prone to developing painful kidney stones Stones in the Urinary Tract Stones (calculi) are hard masses that form in the urinary tract and may cause pain, bleeding, or an infection or block of the flow of urine. Tiny stones may cause no symptoms, but larger stones... read more , blood in the urine Blood in Urine Blood in the urine (hematuria) can make urine appear pink, red, or brown, depending on the amount of blood, how long it has been in the urine, and how acidic the urine is. An amount of blood... read more , and kidney infections Kidney Infection Pyelonephritis is a bacterial infection of one or both kidneys. Infection can spread up the urinary tract to the kidneys, or uncommonly the kidneys may become infected through bacteria in the... read more . Calcium deposits in the kidneys occur in more than half of the people with the disorder. Calcium deposits may form kidney stones. Rarely, stones block the urinary tract Urinary Tract Obstruction Urinary tract obstruction is a blockage that inhibits the flow of urine through its normal path (the urinary tract), including the kidneys, ureters, bladder, and urethra. Blockage can be complete... read more .
A doctor may suspect medullary sponge kidney based on the symptoms and results of imaging tests done for other reasons. Imaging tests of the kidneys reveal calcium deposits if there are any. The diagnosis is usually made by computed tomography Computed tomography There are a variety of tests that can be used in the evaluation of a suspected kidney or urinary tract disorder. (See also Overview of the Urinary Tract.) X-rays are usually not helpful in evaluating... read more (CT), usually showing calcium deposits and widened (dilated) urine-containing tubules in the kidneys.
Most people do well without treatment. Treatment may be necessary if infection develops or if medullary sponge kidney causes calcium to deposit and repeatedly form stones. Treatment for calcium stones is high fluid intake (more than 2 quarts [2 liters] per day) and a diet that is low in sodium, normal in calcium, and low to normal in protein. Sometimes doctors recommend people take a thiazide diuretic to reduce the amount of calcium that is excreted in their urine. Surgery may be needed if the urinary tract becomes blocked. Infections are treated with antibiotics.
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
American Kidney Fund (AKF): Information about kidney disease, kidney transplant, and needs-based financial assistance to help manage medical expenses
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): General information on kidney diseases, including research discoveries, statistics, and community health and outreach programs
National Kidney Foundation (NKF): Information on everything from the basics of kidney function to access to treatment and support for people with kidney disease