How are stones detected?

Sometimes stones do not cause symptoms (silent) and are found on x-rays taken during a general health exam. Such stones usually pass unnoticed and may not need treatment. More commonly people with kidney stones usually end up seeing their doctor because of back pain or blood in their urine. The doctor will need to know about their medical and family history. Kidney stones can be found on a x-ray, ultrasound, or CT scan. The doctor gains valuable information about the stone's size and location from these diagnostic images.

The doctor may decide to scan the urinary tract using a special x-ray test called an IVP (intravenous pyelogram), where a dye is injected into a patient's vein to allow the doctor to locate the stone, evaluate the interior kidney anatomy, and identify the severity of the obstruction. Sometimes if a stone is not seen on x-rays or if the patient has an allergy to the x-ray dye, the patient will undergo a procedure in the operating room called a retrograde pyelogram, where a dye is injected up the ureter.

Results from these various tests help determine the appropriate treatment. It is important that if the stone passes, it is sent to a laboratory for tests. This will allow for analysis and the development of some long-term treatment and prevention. The stone is usually caught by urinating into a type of cup with a strainer. Any abnormal substance that may promote stone formation can be detected from blood and urine tests.