Diagnosis In evaluating your condition, your doctor may perform the following: Physical examination, especially of the abdomen or back Blood test to exam the levels or uric acid or calcium in your blood Urinalysis to look for crystals or red blood cells in the urine or to measure the level of stone-preventing substances Imaging tests may show kidney stones in your urinary tract. CT scans can reveal small stones that abdominal X-rays may miss. If you're pregnant, your doctor may order an ultrasound. Analysis of passed stones. Your doctor may ask you to urinate through a strainer to catch stones that you may pass. A lab analysis will provide the data your doctor needs to confirm the cause of the stone.