General Risk Factors for Kidney Stones
Factors that increase your risk of developing kidney stones include:
Dehydration: This is the most common cause and the easiest to remedy. Kidney stones form when your urine contains more crystal-forming substances than the fluid in your urine can dilute. Therefore, not drinking enough water each day can increase your risk of kidney stones.
Diet: Studies have shown that eating a diet that's high in sodium can increase your risk of certain types of kidney stones. Too much sodium in your diet increases the amount of calcium your kidneys must filter and significantly increases your risk of kidney stones. In addition, diets that are high in protein and sugar can increase your kidney stone risk. At the same time, your urine may lack citrate in your urine, which is known to prevent crystals from being able to adhere to one another, creating an ideal environment for kidney stones to form. For most patients, a low-protein, low-sodium, and moderate-calcium diet is recommended. Specific dietary recommendations will be based upon your stone composition and evaluation of your metabolism.
Family or personal history: If someone in your family has had kidney stones, you're more likely to develop stones than someone without a family history.
Obesity: High body mass index (BMI), large waist size, and weight gain have all been associated with an increased risk of both a single episode and recurrent episodes of kidney stones.
Digestive diseases and surgery: Certain disorders of the digestive system can affect calcium, electrolyte, and water absorption, which may increase your risk of forming kidney stones. Common disorders include gastric bypass surgery and inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis.
Metabolic disorders: Metabolic conditions that may increase your risk of kidney stones include renal tubular acidosis, cystinuria, and hyperparathyroidism.
Urinary tract infections: Patients who suffer from chromic urinary tract infections may form larger stones up in the kidney. These are commonly called struvite or infection stones.
Other Risk Factors of Kidney Stones:
- Anatomical abnormalities that may increase the risk of kidney stones
- Obstruction of the kidney or ureter
- Calyceal diverticulum
- Horseshoe kidney
- Vesicoureteral reflux
- Ureteral stricture
- Medullary sponge kidney
Types of Kidney Stones:
Knowing the type of kidney stone helps determine the cause and may give clues on how to reduce your risk of getting more kidney stones. This is why it is important to attempt to collect the stone for analysis.
Calcium stones - Most kidney stones are calcium stones, usually in the form of calcium oxalate. Oxalate is a naturally occurring substance found in food. Some fruits and vegetables, as well as nuts and chocolate, have high oxalate levels. Dietary factors, high doses of vitamin D, intestinal bypass surgery, and several metabolic disorders can increase the concentration of calcium or oxalate in urine. Calcium stones may also occur in the form of calcium phosphate.
Struvite stones - Struvite stones form in response to urinary tract infection. These stones can grow quickly and become large. If not treated, they can alter function of the kidneys over time.
Uric acid stones - Uric acid stones can form in people who are dehydrated, eat a diet high in protein, or those who have gout.