Causes and Diagnoses

Causes and Diagnoses of Kidney Stones

Kidney stones happen when urine becomes supersaturated with crystals. This can happen if there is:

  • Very low urine volume
  • High or low urine pH (a measure describing acidity)
  • Too much calcium, phosphorous, oxalate, sodium or uric acid

Many conditions can cause you to have kidney stones, such as:

Diagnosing Kidney Stones

You may have certain tests to diagnose kidney stones:

  • CT scan of the abdomen and pelvis. During this exam, you will move through an X-ray tube. You will not need dye or “contrast.” Usually, this exam uses a low dose of radiation unless your physician wants to look for something besides kidney stones.
  • Lab tests. If you have passed kidney stones, your care team can study them to find their chemical makeup. Your care team may also use a blood test to check your kidney function.
  • Kidney or bladder ultrasound. This test uses high-frequency sound waves to make an image of your kidneys or bladder.
  • Urinalysis. Looking at your urine under a microscope can help your care team find an infection or blood.
  • Complete metabolic evaluation and 24-hour urine study. This study can help your care team see if you have a future risk of forming kidney stones.
    • First, your care team will do a blood test to check levels of certain substances, such as body pH, calcium, uric acid, phosphorous, sodium and potassium.
    • Second, you will collect your urine for a 24-hour period. Your care team will then study the different components. This lets your physician create a plan for you to help prevent kidney stones.
  • Vitamin D and parathyroid hormone testing. Your care team may order these tests if your blood work is abnormal.