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- Kidney stone facts
- What is a kidney stone?
- Who is at risk for kidney stones?
- What causes kidney stones?
- What causes kidney stones? (continued)
- What are the signs and symptoms of kidney stones?
- How are kidney stones diagnosed?
- What is the treatment for kidney stones? How long does it take to pass a kidney stone?
- Can kidney stones be prevented?
- What is the prognosis for kidney stones?
What causes kidney stones? (continued)
A number of different medical conditions can lead to an increased risk for developing kidney stones:
- Gout results in chronically increased amount of uric acid in the blood and urine and can lead to the formation of uric acid stones.
- Hypercalciuria (high calcium in the urine), another inherited condition, causes stones in more than half of cases. In this condition, too much calcium is absorbed from food and excreted into the urine, where it may form calcium phosphate or calcium oxalate stones.
- Other conditions associated with an increased risk of kidney stones include hyperparathyroidism, kidney diseases such as renal tubular acidosis, and other inherited metabolic conditions, including cystinuria and hyperoxaluria.
- Chronic diseases such as diabetes and high blood pressure (hypertension) are also associated with an increased risk of developing kidney stones.
- People with inflammatory bowel disease are also more likely to develop kidney stones.
- Those who have undergone intestinal bypass or ostomy surgery are also at increased risk for kidney stones.
- Some medications also raise the risk of kidney stones. These medications include some diuretics, calcium-containing antacids, and the protease inhibitor indinavir (Crixivan), a drug used to treat HIV infection.
- Dietary factors and practices may increase the risk of stone formation in susceptible individuals. In particular, inadequate fluid intake predisposes to dehydration, which is a major risk factor for stone formation. Other dietary practices that may increase an individual's risk of forming kidney stones include a high intake of animal protein, a high-salt diet, excessive sugar consumption, excessive vitamin D supplementation, and excessive intake of oxalate-containing foods such as spinach. Interestingly, low levels of dietary calcium intake may alter the calcium-oxalate balance and result in the increased excretion of oxalate and a propensity to form oxalate stones.
- Hyperoxaluria as an inherited condition is uncommon and is known as primary hyperoxaluria. The elevated levels of oxalate in the urine increase the risk of stone formation. Primary hyperoxaluria is much less common than hyperoxaluria due to dietary factors as mentioned above.