Nephrocalcinosis

Definition

Nephrocalcinosis is a kidney disorder involving deposition of calcium and oxalate or phosphate in the renal tubules and interstitium (the areas between the tubules). These deposits may result in reduced kidney function.

Causes, incidence, and risk factors

Nephrocalcinosis may be caused by a number of conditions:

• Excess excretion of calcium by the kidney
  
• Renal tubular acidosis
  
• Medullary sponge kidney
  
• Hypercalcemia (high calcium levels in the blood)
  
• Renal cortical necrosis
  
• Tuberculosis
  

Fragments of calcium oxalate or calcium phosphate may break free from the kidney and provide nuclei for formation of stones (nephrolithiasis). This may result in obstructive uropathy, possibly leading to eventual Kidney failure if the obstructing stones are not passed in the urine or removed. Nephrocalcinosis may therefore be discovered when symptoms of renal insufficiency/renal failure, obstructive uropathy, or urinary tract stones develop.

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.

Symptoms

There are generally no early symptoms. Later symptoms related to nephrocalcinosis and associated disorders may include the following:

• Increased urine volume or urine output, decreased
  
• Urinary hesitancy (difficulty initiating the flow of urine)
  
• Dribbling of Urinary Incontinence
  
• Decrease in the force of the urinary stream, stream small and weak
  
• Increased Urinary frequency or urgency
  
• A need to urinate at night (nocturia)
  
• Painful urination (burning or stinging with urination)
  
• Feeling of incomplete emptying of the bladder
  
• Blood in the urine
  
• Flank pain or back pain
  o one or both sides
  o progressive
  o severe
  o spasm-like (colicky)
  o may radiate or move to lower in flank, pelvis, groin, genitals