Nephrocalcinosis is a kidney disorder in which there is an increased amount of calcium in the kidneys.
Causes, incidence, and risk factors:
Nephrocalcinosis may be caused by a number of conditions:
Pieces of of calcium oxalate or calcium phosphate may break free from the kidney. The pieces (deposits) enter the kidney tubules and areas in between them. The deposits may result in reduced kidney function. Pieces of calcium may lead to the formation of stones (nephrolithiasis ).
This condition is relatively common in premature infants, partly from intrinsic kidney calcium losses and partly from enhanced calcium excretion when they are given loop diuretics.
There are generally no early symptoms. Later symptoms related to nephrocalcinosis and associated disorders may include:
Signs and tests:
An examination may indicate disorders that occur as a consequence of nephrocalcinosis. For example, it may be discovered when symptoms of renal insufficiency , kidney failure , obstructive uropathy, or urinary tract stones develop.
There may be signs of fluid overload, such as abnormal heart and lung sounds, if kidney function is poor.
Imaging tests can help diagnose this condition. Tests that may be done include:
Other tests may be done to diagnose and determine the severity of associated disorders.
The goal of treatment is to reduce symptoms. The cause of the disorder must be treated. If the cause is type 1 renal tubular acidosis , vitamin D and calcium should not be given to correct bone disorders associated with the condition because this will worsen nephrocalcinosis.
Medications that enhance calcium loss should be discontinued. Never discontinue any medications without consulting your health care provider.
Conditions that result from the disorder should be treated as appropriate.
The outcome varies depending on the extent of complications and the cause of the disorder. Stones can result in obstructive uropathy , possibly leading to eventual kidney failure if they are not passed in the urine or removed.
Prompt treatment of causative disorders, including renal tubular acidosis , may help prevent nephrocalcinosis.