Kidney stones, also known as renal calculi, are solid masses made up of tiny crystals that form in the kidneys. They are usually caused by an excess of certain minerals in the urine and can range in size from a grain of sand to a golf ball. Symptoms of kidney stones can vary and may include severe pain, nausea, vomiting, and the pain may radiate to the lower abdomen and groin. Diagnosis of kidney stones may include a physical exam, urine tests, blood tests and imaging tests such as an ultrasound or CT scan. Treatment of kidney stones depends on the size and location of the stone as well as the severity of symptoms. Treatment may include medications to reduce pain and help pass the stones, shock wave lithotripsy to break up the stones, or surgical removal.