Tests and diagnosis

By Mayo Clinic Staff

During the physical exam, your doctor may check your muscle strength and reflexes. For example, you may be asked to walk on your toes or heels, rise from a squatting position and, while lying on your back, lift your legs one at a time straight in the air. Pain that results from sciatica will usually become worse during these activities.

Imaging tests

Many people have herniated disks or bone spurs that will show up on X-rays and other imaging tests but cause no symptoms. So doctors don't typically order these types of tests unless your pain is very severe or it doesn't improve within a few weeks.

  • X-ray. An X-ray of your spine may reveal an overgrowth of bone (bone spur) that may be pressing on a nerve.
  • Magnetic resonance imaging (MRI). This procedure uses a powerful magnet and radio waves to produce cross-sectional images of your back. MRI produces detailed images of bone and soft tissues such as herniated disks. During the test, you lie on a movable table inside the MRI machine.
  • Computerized tomography (CT) scan. When CT is used to image the spine, you may have a contrast dye injected into your spinal canal before the X-rays are taken — a procedure called a CT myelogram. The dye then circulates around your spinal cord and spinal nerves, which appear white on the scan.
Sep. 19, 2012