Kidney stones account for nearly 3 million doctor visits in the United States each year, according to the National Kidney and Urologic Diseases Information Clearinghouse. While many kidney stones remain very small and leave the body without causing symptoms, some kidney stones grow large enough to cause excruciating pain when they pass from the body. Some people suffer from frequently occurring kidney stones. Although the exact cause of frequent kidney stones is sometimes unknown, doctors have uncovered some factors that may contribute to a higher frequency of kidney stone formation.
Dehydration
The biggest risk factor for frequent kidney stones is chronic dehydration, according to Medline Plus. Kidney stones form from minerals in urine, often calcium. When a person is dehydrated, the volume of water in the urine decreases, which increases the concentration of minerals, a process known as supersaturation. Supersaturated minerals are more likely to form into the crystals that make up kidney stones.
Diet
Calcium often combines with other minerals such as oxalate, phosphate or carbonate to form crystals. Eating foods rich in these minerals, including leafy vegetables, rhubarb, beets, peanuts, chocolate, coffee or tea may increase the frequency of kidney stone formation, particularly when combined with dehydration. Doctors do not think that these foods by themselves trigger kidney stones in otherwise healthy people, but that people who are already at risk for kidney stones may be more likely to develop them after eating these foods. Excess vitamin D intake has also been linked to kidney stones.
Infections and Disorders
Repeated urinary tract infections are another risk factor for frequent kidney stones. The bacteria that causes these infections secrete enzymes that increase the concentration of ammonia in urine. The high levels of ammonia can cause a particular type of kidney stones called struvite stones. Kidney disorders like cystic kidney disease are another risk factor, as are metabolic disorders like hyperparathyroidism, hyperthyroidism and chronic pancreatic disease. Gout, a type of arthritis, increases the levels of uric acid in the body, leading to the frequent formation of uric acid stones. Chronic bowel inflammation is another disorder linked to frequent kidney stones.
Inherited Diseases
Certain inherited diseases greatly increase the risk of frequent kidney stone formation. Cystinuria is a disorder that results in high levels of cystine in the blood and urine, leading to the formation of cystine crystals. Hypercalciuria is another inherited disease that results in excess absorption of calcium from food. The resulting high levels of calcium increase the risk of kidney stone formation. Patients with the inherited disease hyperoxaluria produce excess oxalate, which combines with calcium to form kidney stones. Hyperuricosuria is a disease that increases levels of uric acid in urine, leading to the frequent formation of uric acid stones.
