Definition | Causes | Risk Factors | Symptoms | Diagnosis | Treatment | Prevention


Kidney stones are formed from crystal-like material. 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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The cause of your kidney stone depends on the type of stone that you have. Calcium stones are the most common type.

  • Calcium oxalate or phosphorus stones—Form when there are high amounts of calcium or other minerals in the urine or when minerals that stop stones from forming are too low.
  • Struvite stones—These stones develop because of a urinary tract infection.
  • Uric acid stones—These stones form when urine is acidic. This may also occur in people with gout or those who are on chemotherapy.
  • Cystine stones—due to a rare genetic disorder that causes the kidneys to build up too much 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:


In many people, kidney stones do not cause symptoms and pass with 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


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 depends on the size and location of the kidney stone. Treatment may include one or more of the following:


For small kidney stones, drinking at least 2-3 quarts of water per day can help the body pass the stone out with urine. You may be given a special cup to catch the stone when it passes. The doctor may want to test the stone to see what type it is. IV fluids may be needed in a hospital if you are vomiting.


Pain medication may help with discomfort until the stone passes. You may also be given medication to 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

Ureteral Stent

A stent may be placed temporarily if there is an infection present or too much inflammation to safely remove the stone.


A small tube is passed up through the urinary tract to the ureter. A small camera is passed through the tube so that the doctor can see the stone. The stone can then be removed. General or spinal anesthesia may be needed.

Percutaneous Nephrolithotomy

Percutaneous nephrolithotomy is used to treat large stones located in the kidney. A small incision is made in the lower back. A scope is passed through a tube so the kidney stones can be seen. The stones are then broken into smaller pieces and removed.


Lithotomy is an open surgery used to remove stones. This is rarely used because of the less invasive options available.

Extracorporeal Shock Wave Lithotripsy (ESWL)

ESWL sends shock waves into the body. The impact of the shock waves breaks up the larger stones so they can pass in urine.


Once you have formed a kidney stone, you are more likely to form 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.