Kidney stones (calculi) typically form when your urine becomes too concentrated, causing crystals to separate from the urine and build up inside the kidneys. Stones may be as small as a grain of sand or as large as a golfball. Some stones pass out of the body without the need for intervention, but others can cause severe pain if they become trapped in one of your ureters (the narrow tubes that carry urine from the kidneys to the bladder).
- Male, Caucasian, age 20-60
- Dehydration (not drinking enough water)
- A diet too high in salt, calcium or oxalates (such as spinach, chocolate, nuts), excess vitamin C or D or a high protein diet
- Family history of kidney stones or a previous stone
- Metabolic diseases (such as hyperparathyroidism or gout)
- Inactive lifestyle or prolonged bed rest
- Frequent urinary tract infections or other bladder problems
- Inflammatory bowel disease (IBD) such as Crohn's disease
- Certain rare hereditary disorders
Call your doctor if you experience any of the following symptoms, which may indicate a kidney stone:
- Sudden intense pain in your back or side near your kidney, which may radiate towards your abdomen, groin or genitals
- Nausea and/or vomiting
- Blood in your urine
- Frequent and painful urination
- Fever, especially if accompanied by other symptoms (may be an emergency if a stone is blocking the ureter) Some stones cause no symptoms at all.
In addition to taking a history and physical, your doctor may order one of the following tests to determine if and where a stone exists:
- Plain X-ray ("KUB" of the kidneys, ureters and bladder)
- CT scan or IVP (Intravenous Pyelogram, a special dye test to evaluate your kidneys and ureters)
Many kidney stones do not require treatment or will pass without surgery. However, several procedures exist if your stone needs treatment:
- Extracorporeal Shock Wave Lithotripsy (ESWL) - sound waves pass through the body and break up the kidney stone into smaller, more easily passable fragments.
- Ureteroscopy with Lithotripsy - a special videoscope is passed into the urinary tract, where the stone can be grasped or broken into smaller pieces with a laser.
- Percutaneous Nephrolithotomy -a videoscope is placed directly into the kidney from the back to break up and remove large or complicated stones.
Major surgery (nephrolithotomy) typically is reserved for a small percentage of patients when other methods are not successful.
Reducing Risk of Stone Recurrence
More than half of those who develop one kidney stone will develop recurrent or additional stones. Your doctor may order special urine and blood tests to help determine how to decrease the risk of recurrence. Based upon these results your doctor may suggest you:
- Drink more water
- Reduce salt and/or protein intake
- Avoid foods high in oxalate
- Avoid/reduce caffeine
- Eat a special diet
- Take special medications or antibiotics
- Watch your calcium intake
Your doctor may refer you to a nutritionist for specific dietary guidelines.