Medullary sponge kidney is a kidney disease that is usually present at birth. This disease is a defect of the tubes inside of the kidneys, known as the tubules. As it is formed, urine flows freely through the tubules in individuals with normal kidneys. In an individual with a medullary sponge kidney, cysts form in the inner part of the kidney, known as the medulla. These cysts, which typically have an appearance similar to a sponge, can obstruct the free flow of urine through the tubules.
Normal tubules are small, which means urine can flow through quickly. As the cysts continue to collect in the tubules of an individual with medullary sponge kidney disease, this may cause the tubules to widen. If they are widened too much, the urine may not be able to pass through as efficiently, often passing through very slowly or not at all.
If the body is unable to release an adequate amount of urine within a certain time frame, toxins may start to build up in the system. Kidney stones and infections can occur as a result of slowed urine flow. Urine stored in the body is warm, and this warmth can enable bacteria growth. Bacteria in the urine may make it less acidic, which can lead to kidney stones. Additionally, the bacteria may lead to an infection, such as an urinary tract infection.
There may be no warning symptoms of having medullary sponge kidneys. Individuals with the condition may experience urinary tract infections, blood in the urine, and kidney stones. Commonly, it is the onset of one of these conditions that leads to the discover of medullary sponge kidney disease. Symptoms of urinary tract infections and kidney stones may be similar and can include fever, pain in the lower back, dark urine, a painful or burning sensation while urinating, and foul smelling urine.
Treatment may not be necessary for many individuals living with a medullary sponge kidney. If there is a consistent occurrence of conditions, such as kidney stones or urinary tract infections, the main method of treatment may be to combat those issues singularly. Kidney stones that are too large to pass on their own may be removed through the urethra with a small tube known as a urteroscope. As for urinary tract infections, antibiotics are typically the main course of treatment. The physician making the diagnosis of medullary sponge kidneys will be able to advise if any additional course of treatment will be needed.