Kidney Stones

Kidney stones are diagnosed and treated by the Urology Division of Premier Medical Group. Kidney stones (calculi) are hardened mineral deposits that form in the kidney. They originate as microscopic particles of crystals and develop into stones over time. The medical term for this condition is nephrolithiasis, or renal stone disease.

Crystals and kidney stones may form when an imbalance of minerals occurs in the urine. About 1 in 10 Americans will suffer from kidney stones in their lifetime. Historically, men have stones three times as often as women, but this ratio has decreased over the last decade.

What causes kidney stones?

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Several factors increase the risk for developing kidney stones, including inadequate fluid intake and dehydration, reduced urinary volume, increased excretion of certain minerals in the urine (e.g., calcium, oxalate, uric acid) or decreased excretion of others (magnesium, citrate). Normally, a balance is kept in the levels of these minerals. An imbalance can cause crystals to form, which then bind together into kidney stones. Several medical conditions such as medullary sponge kidney, renal tubular acidosis, hyperparathyroidism, and urinary tract infections (UTIs) may contribute to kidney stones.

Anything that blocks or reduces the flow of urine (e.g., urinary obstruction, congenital abnormalities) also increases the risk. For many Americans, our dietary habits play a very large role – particularly an excess of salt (sodium) and animal meat protein (beef, chicken, fish, pork, etc).

What are the symptoms of kidney stones?

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Kidney stones can be less than 2mm

The discomfort caused by kidney stones can be the most agonizing pain ever experienced by a person. Women often state that renal colic pain is worse than labor. The pain usually begins in the flank region (between the ribs and hips) and radiates to the groin. It can become extremely intense, and then all of a sudden let up as a stone moves.

Other symptoms of kidney stones may include the following: blood in the urine, increased frequency of urination (urinary urgency), nausea and vomiting, pain during urination (stinging, burning), tenderness in the abdomen and kidney region.

Kidney stone complications include kidney damage and scarring, decreased kidney function, obstruction of the ureter, recurrent stones, infections, and renal colic (severe pain that radiates from the kidney region to the abdomen and groin).

How are kidney stones diagnosed?

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Diagnosis of renal stone disease involves a medical history, physical examination, laboratory evaluation, and imaging tests. Fever may indicate a urinary tract infection that requires antibiotics. Laboratory tests include a urinalysis to detect the presence of blood (hematuria) and bacteria in the urine. Other tests include blood tests for creatinine (to evaluate kidney function), BUN and electrolytes (to detect dehydration), calcium (to detect hyperparathyroidism), and a complete blood count (CBC; to detect infection). Radiographic imaging is very important to assess the location and size of the stone(s) as this information will have a great impact on the treatment options. Imaging options include: Ultrasound, plain radiographs (KUB, IVP) and more commonly a CAT scan without any intravenous contrast.

What are the different types of kidney stones?

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Calcium Stones (calcium oxalate or calcium phosphate)

These are the most common type of stones (70%) and can form due to fluid and dietary habits. Some patients inherit a tendency to make stones from their parents. These stones are becoming more common as Americans gain too much weight.

Uric Acid

These stones can be associated with gout and with an excess of animal meat intake. These are the only stones that can be dissolved while still in the body.

Struvite Stones

These are also called infection stones and are caused by infection in the urinary tract (UTI). They are made of magnesium, ammonia, and phosphate. Bacteria in the urinary tract release chemicals that neutralize urinary acid, which enables bacteria to grow more quickly and promotes struvite stone development.

Cystine Stones

These are caused by cystinuria, an uncommon genetic disorder. Cystine is an amino acid in protein that does not dissolve well. This condition (called cystinuria) causes cystine stones that are difficult to treat and requires life-long therapy.

How are kidney stones treated?

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Extracorporeal shockwave lithotripsy (ESWL), or “blasting” of the stones, is a popular treatment for kidney stones.

Many kidney stones pass within several weeks. Stones less than 4 millimeters wide often pass without the need for surgical intervention.

Medications may be used to help pass your stones. Alpha-blockers, such as Flomax, are used most often for this purpose, as they help relax and dilate the ureters. Medications can also be used to dissolve uric acid stones.

Minimally invasive treatments include:

  • Ureteroscopy and Holmium Laser: A small telescope is passed through the bladder and into the ureter where a powerful laser can fragment even the hardest stones. This procedure is performed in the operating room, typically as a same day surgery.

  • Shock Wave Lithotripsy: A machine generates sound waves that pass through the body and focus on the kidney stones. This energy breaks the stone into small sand-like pieces, which generally pass through the urine. General anesthesia is used, and you’ll likely go home the same day.

  • Percutaneous Stone Extraction: This is used for larger stones in the kidney. A small incision is made in your back, a telescope with camera is inserted into the kidney and stone fragments are removed. Most patients stay in the hospital a day or two and return to work shortly thereafter.

  • Metabolic Evaluation: All patients are encouraged to make fluid and dietary changes that will help decrease repeat stone risk. Many patients will also be asked to take simple urine and blood tests that will more accurately explain why they are making stones. This information helps tailor an individual treatment plan.

Dr. Evan Goldfischer and Dr. Paul Pietrow both specialize in the treatment of kidney stones. They see patients in the Poughkeepsie and Kingston locations.

How do you prevent kidney stones?

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The best prevention against future kidney stones is following you physician’s treatment plan. This could mean more regular checkups, and further testing. It could also mean taking medication. Some further testing may include:

  • 24-hour urine sample
  • Blood tests to check for mineral samples
  • Stone analysis to determine the composition of a passed stone

Drinking lots of fluids, especially during warmer weather, can help flush minerals out of your kidneys before they can build up and form stones. Two quarts of fluid daily, preferably water, can really help. Try to keep a bottle of water with you during the day. Drink a glass of water with meals, and when you brush your teeth. The color of your urine can be a helpful indicator of dehydration. Clear or light yellow means you are drinking enough, while dark yellow urine means you should drink more fluids. Eating a healthy diet can help maintain normal levels of minerals in your urine.

  • Avoid excessive amounts of vitamin C.
  • Make sure to incorporate the recommended amount of calcium into your daily diet. Too little or too much can affect your chance of kidney stones.
  • Maintain a healthy weight. Obesity can lead to kidney stones.
  • Limit salt intake, fatty foods, and animal protein.
  • Avoiding foods such as beets, spinach, rhubarb, black tea, and colas can also help.

Preventative Medications

  • Allopurinol: helps reduce the amount of uric acid in the urine
  • Potassium citrate: helps prevent calcium stones. Also helps dissolve uric acid stones
  • Thiazide diuretic: helps reduce the amount of calcium in urine