Definition

Kidney stones are formed from crystal-like substance. These stones form inside the kidneys or other parts of the urinary tract.

There are several types of kidney stones:

  • Calcium oxalate
  • Calcium phosphate
  • Struvite
  • Uric acid
  • Cystine

Kidney Stone

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Causes

The cause of your kidney stone depends on the type of stone that you have. For example:

  • Calcium oxalate or phosphorus stones may form if there are:
    • High amounts of calcium or other minerals in the urine
    • Low levels of minerals that stop stones from forming
  • Struvite stones—form with a urinary tract infection
  • Uric acid stones—form because of acidic urine (may also occur because of gout or chemotherapy)
  • Cystine stones—form because of a rare genetic disorder that causes a buildup of cystine

Risk Factors

Kidney stones are more common in Caucasian men under 50 years old.

Other factors that may increase the chances of kidney stones:

  • Personal history of kidney stones
  • Family history of kidney stones
  • Infections
  • Bedrest

For calcium oxalate or phosphorus stones:

  • High amount of sodium (salt) and oxalate in your diet. Oxalate can be found in green, leafy vegetables, chocolate, nuts, or tea.
  • Not drinking enough fluids and dehydration.
  • Overactive parathyroid gland.
  • Chronic bowel disorders such as Crohn disease or ulcerative colitis.
  • Certain medications called diuretics
  • Calcium-based antacids

Struvite stones:

  • History of urinary infection
  • More common in women

Uric acid stones:

Symptoms

In many people, kidney stones do not cause symptoms. The stones may pass unnoticed in urine. Other people may have symptoms, including:

  • Sharp, stabbing pain in the mid-back that may occur every few minutes and last from 20 minutes to one hour
  • Pain in the lower abdomen, groin, or genital areas
  • Nausea and vomiting
  • Blood in the urine
  • Frequent urge to urinate
  • Burning pain during urination
  • Fever

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done.

Your bodily fluids may be tested. This can be done with:

  • Urine tests and cultures
  • Blood tests

Images may be taken of your kidneys and urinary system. This can be done with:

Treatment

Treatment will depend on the size and location of your kidney stones. Treatment may include one or more of the following:

Drinking at least 2-3 quarts of water per day can help to flush a small stone. You may need to pee into a special cup to catch the stone. Your doctor may want to test the stone to find out what type it is.

Pain medicine may help with discomfort until the stone passes. Other medicine can help pass the stone.

Surgery may be needed if the stones are:

  • Very large or growing larger
  • Causing bleeding or damage to the kidney
  • Causing infection
  • Blocking the flow of urine
  • Unable to pass

A stent may be placed for a short time. The stent will help to keep the passage open to allow the stone to pass. It will help if there is too much swelling in the path that the stone has to pass through.

A small tube is passed up into the tract to the stone. The doctor will pass tools through this tube to remove the stone.

This option may treat large stones that are in the kidney. The doctor will pass a scope through a small cut in the lower back. The stones are then broken into smaller pieces and removed.

Lithotomy is an open surgery used to remove stones. The doctor will need a large incision. It is rarely used. Less invasive options have shorter recovery times.

ESWL sends shock waves into the body. The impact of the shock waves breaks up the larger stones. The smaller pieces should be able to pass with urine.

Prevention

Once you have had a kidney stone, you are more likely to have another. To help reduce the chances of another kidney stone:

  • Drink plenty of fluids, especially water.
  • Talk to your doctor about what diet is right for you. Depending on the type of stone you have, you may have to avoid certain food or drinks.
  • Depending on what type of stone you have, certain medications may be prescribed to keep stones from forming again.