Kidney Stones: Symptoms, Causes, Diagnosis, Treatment, and More

Medically Reviewed By Cynthia Taylor Chavoustie, MPAS, PA-C
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Kidney stones are small pieces of hard, crystallized material that form in the kidney. They are often made up of calcium but can also contain uric acid or amino acids. Kidney stones may be preventable in some cases by ensuring good hydration. Taking a prescribed medication can also be useful if you are part of a high risk population, such as those with a personal history of kidney stones.

Once a stone develops and causes symptoms, treatment may include hospitalization, pain medications, and certain procedures that remove or break apart large stones so that they can move more easily out of the body. Small kidney stones may not require treatment.

Kidney stones can pass out of the body in the urine on their own. On occasion, a kidney stone can get stuck in a ureter and result in potentially serious, or even life threatening, complications. These include kidney infections and kidney damage.

Keep reading to learn more about kidney stones, including their symptoms, causes, diagnosis, and treatment options.

When to seek immediate care

Seek immediate medical care if you or someone you are with has symptoms of passing a kidney stone. Such symptoms include severe flank or abdominal pain, a lack of urination, or bloody urine. Rapid diagnosis and treatment can help reduce the risk of complications.

What are the symptoms of kidney stones?

a man with kidney stones is drinking water
Santi Nuñez/Stocksy United

Small kidney stones or kidney stones that do not move and remain in the kidney may not produce any symptoms. A small kidney stone may pass out of the body

in the urine without causing pain or visible blood in the urine.

When a large kidney stone moves out of the kidney and into the ureter, it causes renal colic. This can lead to:

  • severe, sharp, and stabbing pain in the flank area of the lower back
  • blood in your urine
  • feeling the urge to urinate more frequently
  • difficulty urinating
  • cloudy urine
  • foul smelling urine
  • nausea and vomiting
  • fever and chills

What causes kidney stones?

Kidney stones are tiny hard stones that form in the kidney as a result of a buildup of crystallized material. Kidney stones are often made up of calcium, but they can also contain uric acid or amino acids, which are proteins.

One or more kidney stones can form in one or both kidneys.

Kidney stones begin as tiny specks and may gradually increase in size.

Learn 10 facts about kidney stones here.

What are the risk factors for kidney stones?

Several factors can increase the risk of developing kidney stones. However, not everyone with risk factors will develop kidney stones.

Risk factors for kidney stones include:

  • dehydration, including long-term mild dehydration, which results in the production of smaller amounts of urine that contain a higher concentration of substances that form kidney stones, such as calcium and amino acids
  • a family history of kidney stone formation
  • gout, which is due to higher levels of uric acid
  • a high protein diet
  • high blood pressure
  • intestinal malabsorption
  • being assigned male at birth
  • obesity
  • a personal or family history of certain kidney defects, such as horseshoe kidney
  • pregnancy
  • prolonged exposure to a hot climate or high altitudes
  • prolonged inactivity, such as being bedridden
  • urinary tract infection

Reducing your risk of kidney stones

Not all people at risk of kidney stones will develop them, and not all people who develop kidney stones have risk factors.

You may be able to lower your risk of developing kidney stones by:

  • Avoiding dehydration: This means drinking plenty of water so that your urine is consistently very light or clear. If you exercise vigorously or live at a high altitude or in a hot, dry climate, you will need to consistently drink significantly more fluids than a person who has a moderate exercise level or lives in a more tropical climate or lower altitude.
  • Drinking lemonade made from real lemons: Lemons have qualities that may prevent the formation of kidney stones.
  • Eating a well-balanced diet: Consuming moderate portions of protein can help protect against kidney stones.
  • Following treatment plans: This includes treating conditions such as urinary tract infections and gout.
  • Maintaining a moderate weight: Obesity is a key risk factor for kidney stones.
  • Taking medications as prescribed: This can prevent the formation of certain types of kidney stones.

What are the diet and nutrition tips for preventing kidney stones?

To prevent kidney stones from forming — or to prevent them from recurring if you have had them in the past — your doctor may recommend following a specific diet plan. If necessary, a registered kidney dietitian can help you make changes to your diet to reduce your risk of kidney stones and improve overall kidney health.

Although there is no single diet plan that can prevent kidney stones, some general nutrition tips for kidney stone prevention include the following:

  • Drink plenty of water: This can encourage urine production and flush out the chemicals and minerals that can develop into kidney stones. This is particularly important in the summer months and during activities in which you lose a lot of water through sweat, which can reduce urine output.
  • Avoid foods high in oxalate: This compound helps form calcium oxalate stones, which are the most common types of kidney stones. Foods with naturally high levels of oxalate include:
    • beets
    • black tea
    • chocolate
    • nuts
    • potatoes
    • rhubarb
    • spinach
    • Swiss chard
  • Make sure you are getting enough calcium: This may seem counterintuitive to preventing calcium oxalate stones. In truth, a lack of calcium increases your risk of kidney stones. Doctors recommend consuming 1,000–2,000 milligrams of calcium per day. You can achieve this with three daily servings of dairy foods, such as low fat milk, low fat yogurt, and low fat cheese. It also helps to consume certain fresh fruits and vegetables, including oranges, broccoli, and soybeans.
  • Reduce sodium: This includes table salt and many packaged foods that contain added sodium, such as canned soups, potato chips, condiments, and fast foods. Excess sodium contributes to a loss of calcium, which increases your risk of kidney stones, among other conditions.
  • Limit your intake of animal protein: This is particularly with red meat and organ meats, such as liver and kidney, which can raise levels of uric acid in the body and increase the risk of uric acid stones. Reduce your portions of other animal proteins — including eggs, full-fat dairy, and fish — in favor of plant-based proteins, such as beans, soy, and lentils.

Ask your healthcare professional for guidance before making any significant changes to your diet.

How do doctors diagnose kidney stones?

Some tests your doctor may use to diagnose kidney stones include:

  • Urinalysis: This evaluates a urine sample for the presence of blood or minerals that may indicate a kidney stone.
  • Blood tests: These look for elevated levels of certain minerals that can cause kidney stones.
  • X-rays: In some cases, these can show the location of the kidney stone and reveal how it is affecting the urinary tract.
  • CT scans: These are imaging scans that may or may not use liquid contrast to highlight the location and size of the kidney stone.

Learn about when to contact a doctor for kidney stones here.

What are the treatments for kidney stones?

It is common for a person with a small kidney stone to not be aware of the condition. In fact, the stone may pass out of the body spontaneously without any treatment. However, larger kidney stones that move out of the kidney often require treatment.

General treatment of kidney stones

General treatment of kidney stones includes:

  • drinking fluids or receiving IV fluids to dilute the urine and help flush out a kidney stone
  • taking pain medications, which, for large stones, may require IV administration

Surgical treatment of kidney stones

If a kidney stone does not pass out of the body with fluids and pain medications, it may have become lodged in the ureter. In these cases, a variety of procedures may be considered to remove the stone. These include:

  • Ureteroscopy: A surgeon will pass specialized instruments into the ureter through the bladder to withdraw a kidney stone that has become lodged in the lower third of the ureter. A similar procedure can remove or break apart the kidney stone using a laser or an ultrasonic probe.
  • Extracorporeal shock wave lithotripsy: This procedure is for kidney stones located in the upper ureter or the kidney. A machine pulverizes the kidney stone using painless high energy sound waves.

When kidney damage has occurred, which is rare, it may be necessary to remove the affected kidney. This surgery is known as nephrectomy.

Learn more about the treatment options for kidney stones here.

Other frequently asked questions

The following commonly asked questions have been answered by expert Dr. Cynthia Taylor Chavoustie, MPAS, P.A.-C.

How do you pass a kidney stone?

You can pass a kidney stone by drinking enough fluids or getting fluids through an IV line and urinating as usual. If the stone does not pass this way, specialists may intervene with ureteroscopy or lithotripsy.

What are the warning signs of kidney stones?

Sometimes, there are no warning signs of kidney stones. However, pain on one side — typically in the flank region that wraps around to the front — is the first symptom of a kidney stone. Blood in the urine is another common first symptom of a kidney stone.

What is the main cause of kidney stones?

Dehydration is a major factor in developing kidney stones. High levels of circulating calcium, oxalate, and uric acid in your blood will also increase your risk of kidney stones.

Should you go to the hospital for kidney stones?

Most urgent care facilities and even primary care practices can manage mild to moderate cases of kidney stones. However, if the pain is severe, if you have a fever, if you are vomiting, or if you cannot urinate, it may be a good idea to head to the emergency department of the hospital.

Summary

Kidney stones are common and can range from asymptomatic to very painful. They happen when there is a buildup of calcium, oxalate, and phosphorus in the urine. This causes crystals to form. Sometimes, these pass without a need for medical treatment.

If medical treatment is needed, doctors may recommend surgical procedures to break up or remove the stone. They may also prescribe medications or recommend that you increase your fluid intake.

If you notice any symptoms of kidney stones — such as a sharp pain in the abdomen, blood in your urine, or pain while urinating — you should seek medical attention.

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Medical Reviewer: Cynthia Taylor Chavoustie, MPAS, PA-C
Last Review Date: 2022 May 24
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