How Do Doctors Find the Cause of Pain?


Medically Reviewed by Tyler Wheeler, MD on May 12, 2021

If you have pain, your doctor has many ways to find out what’s causing it. They will ask about your symptoms and your medical history, including any illness, injury, or surgery.

Your doctor will also examine you and may order blood tests or X-rays. Among the tests that can help pinpoint the cause of your pain are:

  • CT scan: Computed tomography scans use X-rays and computers to produce an image of a cross-section of the body. During the test, you lie as still as possible on a table. It will move through a large, doughnut-shaped scanning device. Sometimes, your doctor may inject a solution into a vein before your scan. It can help make it easier to see what’s going on inside. Most CT scans take 15 minutes to an hour.
  • MRI: Magnetic resonance imaging can give your doctor clear pictures without X-rays. This test uses a large magnet, radio waves, and a computer to make images. An MRI can take 15 minutes to more than an hour, depending on the number of images made. For certain MRIs, you’ll need a shot of a contrast material to help make clearer images. Because an MRI uses magnets, some people, such as people who have pacemakers, shouldn’t have one.
  • Nerve blocks: These tests can treat and diagnose the cause of your pain. Your doctor injects something to numb pain (an anesthetic) into nerve locations. They may use an imaging test to find the best right place for the needle. Your response to the nerve block may help find out what’s causing your pain or where it’s coming from.
  • Discography: This test is for people who are considering surgery for their back pain. Doctors also use it when they want to do tests before deciding on a treatment. During this test, a dye is injected into the disk that’s thought to be causing the pain. The dye outlines damaged areas on X-rays.
  • Myelogram: This test is for back pain, too. During a myelogram, a dye is injected into your spinal canal. The test helps identify nerve compression caused by herniated disks or fractures.
  • EMG: An electromyogram allows doctors to check muscle activity. Your doctor puts fine needles into your muscles to measure their response to electrical signals.
  • Bone scans: These help diagnose and track infection, fracture, or other disorders in the bone. A doctor injects a small amount of radioactive material into your bloodstream. The material will collect in the bones, particularly in areas that aren’t normal. A computer then can identify those specific areas.
  • Ultrasound imaging: Also called ultrasound scanning or sonography, this test uses high-frequency sound waves to get images of the inside of the body. The sound wave echoes are recorded and displayed as a real-time image.


Show Sources


National Institutes of Health.

Johns Hopkins Medicine: “Sympathetic Nerve Blocks for Pain.”

PubMed Journals: “The Impact of Discography on the Surgical Decision in Patients with Chronic Low Back Pain.” “Nerve Blocks.”

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