Kidney stones, or renal calculi, are solid masses made of crystals. Kidney stones usually originate in your kidneys. However, they can develop anywhere along your urinary tract, which consists of these parts:

• kidneys
• ureters
• bladder
• urethra

Risk factors for kidney stones

The greatest risk factor for kidney stones is making less than 1 liter of urine per day. This is why kidney stones are common in premature infants who have kidney problems. However, kidney stones are most likely to occur in people between the ages of 20 and 50.

Different factors can increase your risk of developing a stone. In the United States, white people are more likely to have kidney stones than black people.

Sex also plays a role. More men than women develop kidney stones, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Other risk factors include:

• dehydration
• obesity
• a diet with high levels of protein, salt, or glucose
• hyperparathyroid condition
• taking medications such as triamterene diuretics, antiseizure drugs, and calcium-based antacids