A kidney stone (urolithiasis, nephrolithiasis or urinary tract stone disease) is a solid piece of material that forms in a kidney when substances in the urine become highly concentrated. These substances may include uric acid, oxalate, or calcium, which tend to crystallize if the urine is very highly concentrated. Kidney stones vary in size. A small stone may be passed through the urine, causing little or no pain. However, a larger stone can remain in the urinary tract, blocking the urine flow and causing severe pain or bleeding.4 Stones may also form in other parts of the urinary tract such as the bladder.
Factors that may lead to kidney stones: 4,5
- Family history
- Diet - eating high protein, sodium or sugar diets
- Dehydration - low fluid intake, people living in warm climates or those who sweat a lot
- Medical conditions/disorders such as hypercalciuria (too much calcium in the urine), cystic kidney diseases, hyperparathyroidism (overproduction of parathyroid hormone), renal tubular acidosis (failure of kidneys to acidify urine), gout (disorder of uric acid metabolism), blockage of the urinary tract, GI tract surgery, etc.
- Certain medications- diuretics, calcium-based antacids, protease inhibitor antiviral, anti-seizure medication topiramate
Ways to help prevent kidney stones: 4
- Healthy eating, diet, and nutrition
- Drinking 2 to 3 liters of fluid a day is recommended
- Recommendations based on the specific type of kidney stone include the following:
- Calcium Oxalate Stones- reduce sodium and animal protein (meat, eggs and fish); take enough calcium; avoid food high in oxalate (spinach, nuts and wheat bran)
- Calcium Phosphate Stones- reduce sodium and animal protein, take enough calcium
- Uric Acid Stones- limit animal protein
The symptoms of kidney stones include the following: 6