Stones produced within the urinary system are not the disease,
but the end product of the disease process. Scientists suggest
many different causes or factors in stone formation. These factors
1. Genetic disorders
4. Metabolic disturbances
5. Heredity (family history of stone disease)
5. Urinary tract infection
6. Hydration (amount of fluid consumed)
Stones are composed of substances such as calcium oxalate, calcium phosphate and uric acid. Calcium stones are the most common, comprising approximately 90% of urinary stones. A stone may consist entirely of one compound but most stones are a combination of salts. Determining exactly what type of stone an individual has passed can be very important and can help guide treatment for prevention of future stones.
Calcium oxalate is the most common crystal found in stones. Oxalate is produced within the body and can also be obtained through foods such as spinach, rhubarb, strawberries, beer, coffee, tea, cocoa and others. When too much calcium oxalate accumulates in the urine, crystals form and a kidney stone may develop. This imbalance can be the result of certain medication, excess oxalate in the diet or bowel disease that can cause excess absorption of oxalate, such as inflammatory bowel disease or previous gastric bypass surgery.
The most common risk factor for kidney stones is drinking too little fluid resulting in dehydration. This decreases the amount of urine and increases the concentration of elements that accumulate to form stones. In high temperature climates, this risk factor is increased due to fluid losses that occur from sweating.
Urinary tract infections can contribute to certain types of kidney stones and these are called struvite stones.
Stones may also accompany metabolic disturbances resulting in excessive levels of calcium in the blood and urine such as abnormally high absorption of calcium from the gut or hormonal disturbances.
Genetic and/or inherited disorders can cause certain types of stones. This includes a disorder called renal tubular acidosis in which the kidney is unable to clear the body of excess acid and cystinuria, a disorder in which excessive amounts of the amino acid cysteine is excreted into the urine to form stones. Excess oxalate can also be due to overproduction of oxalate by the body, termed hyperoxaluria.
Heredity may also plan an important role in the tendency to form kidney stones, that is, having a relative such as parents or siblings who suffer from the disease.