Sometimes "silent" stones--those that do not cause symptoms--are found on x rays taken during a general health exam. These stones would likely pass unnoticed. More often, kidney stones are found on an x ray or sonogram taken on someone who complains of blood in the urine or sudden pain. These diagnostic images give the doctor valuable information about the stone's size and location. Blood and urine tests help detect any abnormal substance that might promote stone formation. The doctor may decide to scan the urinary system using a special x ray test called an IVP (intravenous pyelogram). The results of all these tests help determine the proper treatment.