Kidney stones are hardened mineral deposits that form in the kidneys. They start out as microscopic particles or crystals that develop into stones over time. The medical term for this condition is nephrolithiasis, or renal stone disease.
Your kidneys filter waste products from the blood and add them to the urine produced in the kidneys. When waste materials in the urine do not dissolve completely, crystals and kidney stones may form. These stones may pass out of the kidney and become lodged in one of the ureters, the two tubes that carry urine from the kidneys to the bladder.
Kidney stones typically cause very severe pain that begins in the lower back and radiates to the groin. A lodged stone can block the flow of urine, causing pressure to build in the affected tube and kidney. The increased pressure results in stretching and spasm of the structures, which cause the severe pain.
The most common causes of kidney stone formation include:
Anyone can develop kidney stones, but they most often occur in people between the ages of 30 and 45. Roughly 10 percent of people develop kidney stones, but men are three times more likely to develop them than women. The risk for developing kidney stones declines in people over the age of 50. People who have a sibling or parent with the condition also experience a higher incidence of renal stone disease.
Treatments vary depending upon the type and size of the stone. To pass a small stone, your doctor may ask you to significantly increase your water intake, take a pain reliever, or perhaps take an alpha blocker, a medication that relaxes the muscles of the ureter and helps you pass the stone faster. Larger stones may require treatment with sound waves to break up a stone so it passes more easily. Some kidney stones require surgical removal.