What Increases Your Risk

Several factors make it more likely you will get kidney stones. Some of these you can control, and others you cannot.

Risk factors you can control

Risk factors for both new and recurring kidney stones that you can control include:

• Fluids you drink.
  • The most common cause of kidney stones is not drinking enough water. Try to drink enough water to keep your urine clear (about 8 to 10 glasses of water a day).
  • Drinking grapefruit juice may increase your risk for developing kidney stones.
• Diet. If you think that your diet may be a problem, schedule an appointment with a dietitian and review your food choices.
  • Vitamins C and D can increase your risk of kidney stones when you take more than the daily recommendations. Read supplement labels carefully, and do not take more than the recommended daily doses.
  • Levels of calcium affect your risk of kidney stones. Getting your recommended amounts of calcium combined with a low-sodium, low-protein diet may decrease your risk of kidney stones.⁷ In older people and younger women, one study shows that eating more calcium-rich foods reduces the risk of kidney stones.⁸
  • Diets high in protein, sodium, and oxalate-rich foods, such as dark green vegetables, increase your risk for developing kidney stones.
• Weight and weight gain. Weight gain can result in both insulin resistance and increased calcium in the urine, which can result in a greater risk for kidney stones. In one study, weight gain since early adulthood, a high body mass index (BMI), and a large waist size increased a person's risk for kidney stones.⁹
• Activity level. People who are not very active may have more problems with kidney stones.
• Medicine. Some medicines, such as acetazolamide (Diamox), or indinavir (Crixivan), can cause kidney stones to form.

Risk factors you cannot control

Risk factors for both new and recurring kidney stones that you cannot control include:

• Age and gender.
  • Men between the ages of 30 and 50 are most likely to get kidney stones.³
  • Postmenopausal women with low estrogen levels have an increased risk for developing kidney stones. Women who have had their ovaries removed are also at increased risk.
• A family history of kidney stones.
• A personal history of frequent urinary tract infections.
• Other diseases or conditions, such as inflammatory bowel disease, hyperparathyroidism, cystic fibrosis, gout, or high blood pressure.
• Insulin resistance, which can occur because of diabetes or obesity.
• Prolonged bed rest.
• Bladder problems caused by spinal cord injury.
• Medicines used to control other conditions or diseases, such as antacids or aspirin.
• An abnormal urinary tract, such as the kidneys being joined (horseshoe kidneys).

Risk factors for recurring kidney stones that you cannot control include:¹⁰

• High levels of minerals, such as oxalate, calcium, and uric acid, in the urine.
• Low urine output (stasis).
• Low levels of citrate. Citrate helps prevent stone formation in some people.
• Abnormal urine pH, either very high or very low, over time.