Kidney Stones

Urology: Kidney Stones

What are Kidney Stones?

Kidney stones are one of the most common disorders of the urinary tract, affecting one in 11 people in the United States. At Mount Sinai South Nassau we have extensive experience diagnosing and treating kidney stones of all types and sizes.

The kidneys function as a filter for the body, removing waste products from the bloodstream and then removing them from the body in the form of urine. Kidney stones happen when the mineral waste deposits in the kidney are not removed by urination. These deposits can build up and cause blockage inside the kidney or can get caught in the ureter (the tube going from the kidney to the bladder). Kidney stones can be as small as a grain of sand or as large as a lemon.

Kidney stones can form for various reasons, such as an imbalance in the chemical composition of urine, inadequate fluid consumption, poor diet (one high in fats, sodium, and sugars), blocked or restricted urine flow, or certain diseases (i.e., gout, colitis, and arthritis).

Stones begin in the kidney and either stay there or slowly move down the ureter (the tube connecting the kidney to the bladder) to reach the bladder before passing through the urethra (the canal that you urinate through). Small stones with smooth exteriors may not cause any symptoms, but larger stones, or ones with rough exteriors can be painful as they try to leave your body.


You might not realize right away that you have a kidney stone. When the stone is still in your kidney, you might not feel it. If the stone is very small, it might be able to move through your urinary tract and leave your body with urine, without causing any problems.

However, when a stone travels to your ureter (tube leading from your kidney to the bladder), you will likely feel symptoms. Kidney stones are sometimes considered "the great mimicker" because their signs and symptoms are very similar to appendicitis, ovarian or testicular conditions, gastritis, and urinary tract infections. You may not feel pain in your kidneys; you may feel it elsewhere, due to pain referral patterns.

The most common signs and symptoms of kidney stones include:

  • Burning during urination
  • Flank pain (e.g., pain in the side of the abdomen, toward the back)
  • Frequent and/or urgent urination
  • Groin pain
  • Nausea and vomiting
  • Pain in the testicles
  • Pain overlying the bladder
  • Recurring urinary tract infections
  • Visible or microscopic blood in the urine (hematuria)

Symptoms can be mild to severe and unrelenting. Classic kidney stone pain is often referred to as "colic," which implies that the pain comes and goes. In reality, kidney stone pain can be constant and severe and make it extremely difficult to find a comfortable position.


Often, kidney stones do not have one singular cause. Multiple factors can cause kidney stones to form, including genetic, environmental, dietary, and medical issues. Among the most important factors are:

  • Calcium supplements
  • Certain medications (such as topiramate and furosemide)
  • Dehydration
  • Diabetes
  • Diseases causing metabolic acidosis
  • Family history of stone disease, generally only in the case of cysteine stones
  • Gastric bypass or lap-band surgery
  • Gastrointestinal diseases (such as ulcerative colitis or Crohn's disease)
  • Hyperparathyroidism
  • Living in geographic areas with high incidence of stone disease
  • Sarcoidosis


Approximately two-thirds of patients who have had one kidney stone are at risk for developing another in the future. Because of this high rate of recurrence, Mount Sinai South Nassau physicians recommend a metabolic evaluation which includes stone analysis, blood, and urinary testing. We perform bone density measurements when needed. This evaluation can identify the source of problem in more than 90 percent of patients and can help us determine how you might be able to prevent future kidney stones.

While there is no guaranteed way to prevent stones from forming (heredity does play a role), you can reduce your risk by modifying your diet. Here are some steps that you can take.

  • Increase fluid intake to about two to three liters per day, depending on your activity level and rate of perspiration. Water is best, though citrus drinks such as lemonade and orange juice have also been shown to help prevent kidney stones.
  • Limit salt/sodium intake to no more than 2,300 milligrams a day. Sodium causes the kidneys to excrete more calcium, which increases the chance of developing kidney stones. You can monitor sodium intake by reading food labels.
  • Adjust calcium supplementation, which can affect formation of calcium oxalate stones. Calcium from food does not increase stones, but some studies have shown that supplements can affect formation of certain stones, if not taken with meals. Your doctor can advise you on the most appropriate calcium levels, if you have a history of forming calcium oxalate stones.
  • Reduce animal protein to no more than six ounces a day. Meats and other animal protein, like eggs and fish, can encourage formation of uric acid stones because they contain purines. Reducing meat consumption can decrease the risk of uric acid stones, especially if you have already had them.
  • Avoid foods high in oxalate. People who are more likely to form calcium oxalate stones should avoid foods high in oxalate such as beets, spinach, many types of berries, sweet potatoes, soy, nuts, chocolate, brewed tea, and colas.
  • Consult a dietician for more individualized advice. If you are prone to developing kidney stones, a dietician with expertise in kidney stone prevention may help you identify foods to limit or avoid. We will develop an individualized treatment plan, depending on the type of stones you have had.


Our urologists have a direct link to local imaging centers so that we can easily see the size and location of a patient’s stone. This helps us determine the best treatment options for stones. Luckily, there are many treatment options for kidney stones, almost all of which are minimally invasive.

  • Observation and medical therapy: Many small stones pass on their own, and do not need surgery. Certain medications have been shown to help stones pass, and we work to make patients as comfortable as possible while they pass their stone.
  • Dissolving stones with medication: Medication can be used to dissolve a type of stone made of uric acid. We assess whether a patient has uric acid stones, and if so, we try to dissolve the stone with a simple oral medication. This helps many patients avoid surgery.
  • Shock-wave lithotripsy: High-powered shock waves can break-up stones without the need for an invasive surgery. After breaking up the stone, the patient then passes the small fragments on their own. Patients go home the same day, and recovery is very fast, with minimal discomfort or side effects. Starting in 2018, we utilize the latest generation equipment to perform SWL. This equipment allows us to perform the procedure on larger patients, and also on stones that are not visible with x-ray. We are typically able to offer patients shock-wave within 48 hours of seeing them.
  • Laser lithotripsy: Not all stones can be broken with shock wave. For those stones, a tiny laser can be used like a jackhammer to break up the stones. The fragments are then plucked out of the kidney with a basket. This is a minimally invasive procedure, and no incisions are necessary. Patients go home the same day, and typically have minimal discomfort afterwards. Our digital camera provide the best possible view of the stones, and our laser system is also of the most recent generation. With this laser system, we are able to break up even very large stones without the need for an incision.
  • Staghorn stones: Some stones fill up the entire kidney, and are known as staghorn stones. For these stones, we can perform a percutaneous nephrolithotomy (PCNL), which is a minimally invasive procedure performed through a small hold in the kidney to break up and remove the stone.
  • Metabolic evaluation: For patients who are repeat stone formers, have certain medical conditions, or have a family history of stones, we perform a metabolic work-up to evaluate their diet and hormone levels to reduce the risk of more stones. Most of the time, dietary changes are all that are needed, but medications can also be used to help prevent additional stones.
  • MOSES technology is a platform that manipulates the holmium laser waveform delivering holmium energy over two pulses. The approach allows MOSES to deliver more energy to kidney stones, achieve finer fragmentation, and produce less retropulsion, which improves visualization and spontaneous stone clearance for laser lithotripsy.

Contact Info

Mount Sinai Doctors - Rockville Centre, Urology and Urogynecology
2 Lincoln Avenue, Suite 102
Rockville Centre, NY 11570
Phone: 516-390-2850
Fax: 516-390-2855

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