Kidney stones are small, solid masses of crystals formed from salt and minerals that originate in the kidney, but which may be found at any point in the urinary tract. While usually a minor condition, they can increase the risk of urinary tract infections and kidney damage. They are a more serious condition for patients with one kidney, kidney transplant recipients, and those with an impaired immune system. 

Symptoms of kidney stones include discolored or bloody urine (often with a foul smell), nausea, vomiting, chills, fever, a frequent need to urinate, and producing small quantities of urine. Kidney stones can be a very painful condition, particularly when stones start to travel down the ureters. Another sign of kidney stones is a pain in the back or abdomen, which radiates to the groin. 

Kidney stones normally pass on their own, but in some cases, surgery to remove the stones may be required. Generally, kidney stones are treated by drinking more water and with medication. Drug classes commonly used to treat kidney stones are alkalinizing agents and potassium supplements.