A risk factor is something that raises your chances of getting a health problem.

Kidney stones are more common in people who have had them before. They also tend to run in families.

The chances of kidney stones are also higher for people who:

• Are White or Asian
• Are under 40 years old
• Had stones develop when they were a child
• Had certain types of stones such as uric acid or those caused by an infection
• Have certain problems with their genes that make stone formation easier
• Take certain medicine such as allopurinol, penicillin, vitamin C, or loop diuretics
• Do not drink enough fluids—this may be more of a problem in warm climates
• Have high intakes of:
  • Oxalates—found in berries, spinach, rhubarb, chocolate, or tea
  • Salt
  • Calcium—can also happen with not getting enough calcium
  • Vitamins C and D
• Have health problems such as gout, obesity, how the body uses insulin, or an overactive parathyroid gland