Exams and Tests

The classic presentation of renal colic associated with blood in the urine suggests the diagnosis of kidney stone. Unfortunately, many other conditions can mimic this disease, and the physician or healthcare provider may need to order tests to confirm the diagnosis. There should always be a concern about the possibility of a leaking abdominal aortic aneurysm when dealing with a patient who presents with the typical symptoms of a kidney stone.

Physical examination is not very helpful in patients with kidney stones, aside from the finding of flank (side of the body between the ribs and hips) tenderness. The examination is often directed to ensuring that other potentially dangerous diagnoses don't exist. As examples, when examining the abdomen, the physician will be looking for a palpable mass that pulsates, which may be a sign of an aneurysm. Tenderness under the right rib cage margin may signal gallbladder disease.

Symptom control is very important, and medication for pain and nausea may be provided before the confirmation of the diagnosis occurs.

A urinalysis will show whether there is blood in the urine. It is also done to ensure that there is no infection associated with the kidney stone.

Blood tests are usually not done, except when the physician has concerns about the diagnosis or is worried about kidney stone complications.

CT scanning of the abdomen is the diagnostic test of choice. It is done without asking the patient to drink contrast material to outline the bowel and without intravenous dye injection. The scan will show the anatomy of the kidneys, ureter, and bladder and will show if a stone exists, how big it is, and how much blockage it is causing. The CT also demonstrates many other organs in the abdomen, like the appendix, pancreas, and aorta and may give extra information in case the preliminary diagnosis of kidney stone was wrong.

Ultrasound is another way of looking for kidney stones and obstruction and may be useful when the radiation risk of a CT scan is unwanted (for example, if a woman is pregnant).

In those patients who already have the diagnosis of a kidney stone, plain abdominal x-rays may be used to track its movement down the ureter toward the bladder.