Kidney stones

Diagnosis

Diagnosis involves the steps that your healthcare professional takes to find out if you have kidney stones. Diagnosis also can include testing to find the cause and chemical makeup of kidney stones. Your healthcare professional starts by giving you a physical exam. You also may need tests such as:

• Blood tests. Blood tests may reveal too much calcium or uric acid in your blood. Blood test results help track the health of your kidneys. These results also may lead your healthcare professional to check for other health conditions.
• Urine testing. Your healthcare professional may ask you to collect samples of your urine over 24 hours. The 24-hour urine collection test may show that your body is releasing too many stone-forming minerals or too few substances that prevent stones. Follow your healthcare professional's instructions closely. Collecting the urine appropriately is key to make changes in your treatment plan to prevent new stones from forming.

• Imaging. Imaging tests such as CT scans may show kidney stones in your urinary tract. An advanced scan known as a high-speed or dual energy CT scan may help find tiny uric acid stones. Simple X-rays of the stomach area, also called the abdomen, are used less often. That's because this kind of imaging test can miss small kidney stones.

  Ultrasound is another imaging option to diagnose kidney stones.

• Analysis of passed stones. You may be asked to urinate through a strainer to catch any stones that you pass. Then a lab checks the chemical makeup of your kidney stones. Your healthcare professional uses this information to find out what's causing your kidney stones and to form a plan to prevent more kidney stones.
• Genetic testing. Some rare conditions that pass from parent to child make kidney stones more likely. For instance, having cystinuria raises the risk of cystine stones. Primary hyperoxaluria raises the risk of calcium oxalate stones. If your healthcare professional thinks you might have such a condition, your healthcare professional may recommend genetic testing to find out for sure.

Treatment

Treatment for kidney stones varies. It depends on the type of stone and the cause.

Small stones with few symptoms

Most small kidney stones don't require invasive treatment such as surgery. You may be able to pass a small stone by:

• Drinking water. Drinking as much as 2 to 3 quarts (1.8 to 3.6 liters) a day likely will keep your urine dilute and may prevent stones from forming. Unless your healthcare professional tells you otherwise, drink enough fluid. It's ideal to mainly drink water to produce clear or nearly clear urine.
• Pain relievers. Passing a small stone can cause mild to serious discomfort. To relieve mild pain, your healthcare professional may recommend pain relievers such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve). For serious pain, other treatments in the emergency room may be needed.
• Other medicines. Your healthcare professional may give you a medicine to help pass your kidney stone. This type of medicine is known as an alpha blocker. It relaxes the muscles in your ureter. This helps you pass the kidney stone more quickly and with less pain. Examples of alpha blockers include tamsulosin (Flomax) and the drug combination dutasteride and tamsulosin (Jalyn).

Large stones and those that cause symptoms

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Parathyroid glands

Parathyroid glands

The four tiny parathyroid glands, which lie near the thyroid, make the parathyroid hormone. The hormone plays a role in controlling levels of the minerals calcium and phosphorus in the body.

Kidney stones that are too large to pass on their own may need more-extensive treatment. So might stones that cause bleeding, kidney damage or ongoing urinary tract infections. Treatments may include:

• Using sound waves to break up stones. For some kidney stones, your healthcare professional may recommend a treatment called extracorporeal shock wave lithotripsy. This also is known as ESWL. But it depends on the size and location of your stones.

  ESWL uses sound waves to create strong vibrations called shock waves that break the stones into tiny pieces that can be passed in urine. The treatment lasts about 45 to 60 minutes. It can cause moderate pain, so you may be given medicines to prevent pain or help relax you.

  ESWL can cause blood in the urine and bruising on the back or stomach area. It also can cause bleeding around the kidney and around other nearby organs. It can cause discomfort as the stone fragments pass through the urinary tract too.

• Surgery to remove very large stones in the kidney. A surgery called percutaneous nephrolithotomy (nef-row-lih-THOT-uh-me) involves removing a kidney stone using small telescopes and tools inserted through a small cut in the back or side.

  You receive medicine called a general anesthetic that prevents pain and puts you in a sleep-like state during the surgery. You'll likely recover in the hospital for 1 to 3 days afterward. Your healthcare professional may recommend this surgery if ESWL doesn't help you enough.

• Using a scope to remove stones. To remove a smaller stone in your ureter or kidney, your surgeon may use a thin lighted tube called a ureteroscope. This instrument is equipped with a camera. The surgeon places the uteroscope through the urethra and bladder to the ureter.

  Once the stone is found, special tools can snare the stone or break it into pieces that will pass in the urine. Then the surgeon may place a small tube called a stent in the ureter to relieve swelling and support healing. You may need general or local anesthesia during this procedure.

• Parathyroid gland surgery. Some calcium phosphate stones are caused by overactive parathyroid glands. These glands are located on the four corners of the thyroid gland, just below the Adam's apple. When these glands make too much parathyroid hormone, that's a condition known as hyperparathyroidism. The condition can cause calcium levels to become too high, and kidney stones may form as a result.

  Hyperparathyroidism sometimes happens when a small tumor that isn't cancer forms in one of the parathyroid glands. Or hyperparathyroidism can happen if you develop another condition that leads these glands to make more parathyroid hormone. Removing the tumor from the gland stops kidney stones from forming. Or your healthcare professional may recommend treatment of the condition that's causing your parathyroid gland to make too much of the hormone.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.

Preparing for your appointment

Small kidney stones that don't block your kidney or cause other health troubles can be treated by your primary healthcare professional. But if you have a large kidney stone and have serious pain or kidney troubles, you may need to see a specialist. Your healthcare professional may refer you to a doctor called a urologist or a nephrologist who treats conditions of the urinary tract.

What you can do

To prepare for your appointment:

• Ask if there's anything you need to do before your appointment, such as limit your diet.
• Write down your symptoms, including any that don't seem related to kidney stones.
• Keep track of how much you drink and urinate during a 24-hour period.
• Make a list of all medicines, vitamins or other supplements that you take.
• Take a family member or friend along, if possible, to help you remember what you discuss with your healthcare professional.
• Write down questions to ask your healthcare professional.

For kidney stones, some basic questions include:

• Do I have a kidney stone? If so, what size and type of stone is it, and where in my urinary tract is it?
• Will I need medicine to treat my condition?
• Will I need surgery or another procedure?
• What's the chance that I'll develop another kidney stone? How can I prevent kidney stones in the future?
• I have other health conditions. How can I best manage them together?
• Should I see a specialist? If so, does insurance typically cover the services of a specialist?
• Do you have any educational material that I can take with me? What websites do you recommend?

Feel free to ask any other questions during your appointment.

What to expect from your doctor

Your healthcare professional is likely to ask you questions such as:

• When did your symptoms start?
• Have your symptoms been constant or do they happen once in a while?
• How bad are your symptoms?
• What, if anything, seems to make your symptoms better?
• What, if anything, appears to make your symptoms worse?
• Has anyone else in your family had kidney stones?