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Kidney and uretal stones

Painful materials that become concentrated in the urinary system

Kidney stones are one of the most common disorders of the urinary tract, resulting in more than a million visits to health care providers – including 300,000 visits to emergency rooms – each year, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

A kidney stone is a solid piece of material that forms in a kidney when substances that are normally found in the urine – such as calcium, oxalate or phosphorous -- become highly concentrated. A stone may stay in the kidney or travel down the urinary tract. Kidney stones, which vary in size, may pass on their own or get stuck along the urinary tract, blocking the flow of urine and causing severe pain or bleeding.

Although anyone can get a kidney stone, some people are more likely than others. Men are affected more often than women, and stones are more common in non-Hispanic white people than in non-Hispanics, African Americans and Mexican Americans. Also, overweight and obese are more likely to get kidney stones.

In addition, people with certain health conditions such as hyperparathyroidism, cystic kidney disease or gout, have an increased risk of kidney stones. 

Diagnosis and treatment

A health care provider can order urinalysis or blood tests to determine if you have a kidney stone. Abdominal X-rays or CT scans also can help determine if you have a stone.

Treatment for stones depends on their size, what they are made of and whether they are causing pain or obstructing the urinary tract. Small stones can pass on their own, especially if you drink plenty of fluids to help them move along.

Larger stones may require:

  • Shock wave lithotripsy, in which a machine called a lithotripter is used to crush the kidney stone. The machine creates shock waves that pass through a person’s body and break the kidney stone into smaller pieces that can be passed through the urinary tract.
  • Ureteroscopy, in which a long, tubelike instrument with an eyepiece, is used to find a retrieve the stone with a small basket or break it up with laser energy.
  • Percutaneous nephrolithotomy, a process by which a wire-thin instrument called a nephroscope is used to locate and remove the stone. A tube is inserted directly into the kidney through a small incision in a person’s back. 

Prevention

People can help prevent kidney stones by making changes in their fluid intake. Health care providers recommend that a person drink 2-3 liters of fluid a day. Though water is best, other fluids such as citrus drinks may help prevent kidney stones.

Depending on the type of kidney stone a person has, changes in the amounts of sodium, animal protein and oxalate consumed can also help. Recommendations include:

Calcium Oxalate Stones

  • Reducing sodium
  • Reducing animal protein, such as meat, eggs, and fish
  • Getting enough calcium from food or taking calcium supplements with food
  • Avoiding foods high in oxalate, such as spinach, rhubarb, nuts, and wheat bran

Calcium Phosphate Stones

  • Reducing sodium
  • Reducing animal protein
  • Getting enough calcium from food or taking calcium supplements with food

Uric Acid Stones

  • Limiting animal protein