A kidney stone, also known as renal calculi or nephrolithiasis, is a hardened mass of mineral and acid salts that separates from the urine and travels through the urinary tract. The urine normally dilutes and dissolves these substances, but when the composition of urine is unbalanced, crystallized stones can form. Kidney stones are a common but painful urinary tract disorder and men are more likely than women to experience them. Kidney stones can cause severe pain, however they usually do not cause any permanent damage to the urinary tract or body.
Causes of Kidney Stones
Kidney stones can form when substances in the urine such as calcium, oxalate, and phosphorus, become highly concentrated. While the exact cause of kidney stones is not always known, certain people may have an increased risk of kidney stones. This may include those with:
- Family history of kidney stones
- Gout
- Chronic diarrhea
- Crohn's disease
- Obesity
- A high level of calcium in the urine
People who do not drink enough fluids may have a higher risk for developing kidney stones, as their urine is more concentrated. Certain medications may also increase the risk of kidney stones.
Symptoms of Kidney Stones
Most kidney stones cause terrible pain as they move through the urinary tract and into the ureter. Common symptoms include:
- Severe pain in the lower side and back
- Pain radiating to the abdomen and groin
- Bloody or cloudy urine
- Frequent and painful urination
- Nausea
- Vomiting
- Fever
Pain caused by a kidney stone may increase in intensity as the stone moves through the urinary tract.
Diagnosis of Kidney Stones
Kidney stones are diagnosed through a physical examination and a review of symptoms. Diagnostic tests may include:
- Blood tests
- Urine tests
- Intravenous pyelogram (IVP)
- CT scan
Kidney stones can often be identified on X-rays, sometimes before they cause any symptoms. The X-rays can show the location of stones in the kidney or urinary tract.
Treatment of Kidney Stones
Treatment is not usually necessary for small kidney stones as most stones typically pass on their own after drinking plenty of water. Pain medication may be prescribed to relieve symptoms. Larger stones that cannot pass on their own or that block the urinary tract, may require more aggressive treatment methods to locate the stone and break it up into tiny pieces so it can pass through the urine. This may be performed through a procedure known as a shock wave lithotripsy (SWL) or a ureteroscopy. In severe cases, more-invasive surgery may be necessary to remove very large stones.
Prevention of Kidney Stones
While all kidney stones cannot be avoided, certain lifestyle changes may help reduce the risk of developing kidney stones. These may include:
- Drinking plenty of fluids
- Reducing fat intake
- Eating a low-salt diet
Medication may be prescribed to help control the amount of minerals and acid in the urine of people who may be prone to developing kidney stones. People who have had previous kidney stones are more likely to have a recurrence, but implementing these changes may help to reduce future risk.