Medullary sponge kidney is an uncommon disorder in which the urine-containing tubules of the kidneys are dilated.
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, blood in the urine, and kidney infections. 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.
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 (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.
More Information
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
