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Kidney Stones

What are Kidney Stones?

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When certain minerals become concentrated in the urine, they can crystalize in our kidneys. Most of the time, these crystals are small and pass without pain. But if the crystals collect together, they can form masses called kidney stones. In the kidney, these masses usually bring no symptoms if they don’t block the flow of urine. However, if kidney stones migrate down the urinary tract from the kidney to the bladder, they may cause pain and blood in the urine.When the kidney is blocked by a stone, urine can back up in the blood, posing potential damage to kidney tissues and causing infection.

How Erlanger Can Help

Erlanger Urology is a major teaching and research center in the management of kidney stones and is home to the region's only dedicated kidney stone clinic. Our goal is to help patients prevent kidney stones, and when intervention is needed, provide the latest minimally invasive techniques to remove them.We are continuously developing new technologies to minimize pain, bring healing and deliver positive outcomes.

Who is at risk?

Men are more likely than women to have kidney stones. However, pregnant women also face a higher risk of developing them. Kidney stones are usually an adult condition, occurring between the ages of 20–49, but they can occur in children as young as five.

Causes of Kidney Stones

  • Insufficient fluid intake – especially during exercise – can bring dehydration and cause minerals to concentrate and crystalize in the urine.
  • Certain drugs and medical disorders predispose people to kidney stones.
  • Foods high in salt and sugar (including high fructose corn syrup) and low in fluids are a key risk factor for children.
  • Family medical history and the environment are also factors.

Types of Kidney Stones

  • Calcium stones – Most kidney stones are calcium oxalate or calcium phosphate. The more common oxalate stones are caused by too much calcium oxalate in the urine. The less common phosphate stones result from autoimmune diseases and certain drugs.
  • Uric Acid stones – The breakdown of animal proteins in our bodies increases the level of uric acid in our urine, and can cause these stones to form. Gout and chemotherapy are risk factors.
  • Struvite stones – These stones consist of magnesium ammonium phosphate and/or calcium carbonate. Often called “infection stones,” they are caused be bacterial infections of the urinary tract.
  • Staghorn stones – These large, branching stones of any kind (usually a mix of stuvite and calcium) take up a large part of the urinary system. Often containing bacteria, they can seriously damage the kidney if untreated, or cause life-threatening blood infections
  • Cystine stones – These stones result from an inherited genetic disorder called cystinuria. The body doesn’t properly transport the cysteine amino acid, causing accumulation in the urine and the formation of cystine stones.

Symptoms of Kidney Stones

  • Severe abdominal pain
  • Flank or low back pain
  • Groin pain
  • Blood in the urine (visible or discovered in a lab examination)
  • Nausea, vomiting, chills and fever (associated with obstruction)
  • Urination changes and testicular pain (in men)
  • Inability to urinate or frequent and urgent urination


If kidney stones are suspected, your Erlanger urologist will order blood and urine tests, an ultrasound scan, abdominal x-rays and possibly a CT scan. You’ll also need to provide information about your medical history including diet, fluid intake, family history, lifestyle and any medical conditions.


The treatment options available to you will depend on your symptoms—as well as the size, location and type of the kidney stones.

Let Stones Pass Naturally

Small kidney stones will usually pass out of your body through the urinary tract in about two days, with increased fluid intake. Your urologist may prescribe medications to ease the pain, and help the stone pass more easily (Flomax).

Surgical Treatment

If the stone is too large, causes untreatable pain or dehydration, blocks the flow of urine, or accompanies an infection, surgery may be needed. As a nationally-renowned teaching and research center, Erlanger Urology offers the latest, minimally invasive stone removing procedures using digital scopes, holmium laser, and dual ultrasonic/pneumatic lithotripsy including ureteroscopy, percutaneous nephrolithotomy, and shock wave lithotripsy.

Medical Management

Kidney stones are associated with chronic conditions driven by lifestyle and diet including diabetes, obesity, hypertension, and chronic kidney disease. Therefore, your urologist will consider these issues in developing a plan to prevent or manage kidney stones over time. Typical recommendations include:

  • Drink more water – Dehydration is a key risk factor for kidney stones
  • Change your diet – For uric and cystine acid stones, you may be asked to limit sodium and protein intake (especially non-dairy animal protein for uric stones). Supplementing your diet with potassium citrate may help make your urine less acidic.
  • Take prescribed medications – This could include diuretics to help the kidneys remove fluids, or drugs to reduce your uric acid levels.

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