Diagnosis of Low Back Pain and Sciatica
Your healthcare provider will ask about your symptoms and medical history. A physical exam will be done. Your back, hips, and legs will be tested for strength, flexibility, sensation, and reflexes.
Often, patients with pain may feel an urgent need to have a medical test. Medical tests are not routinely required for back pain and sciatica. Most episodes of acute back pain resolve on their own over several weeks. In these cases, the information from an x-ray or MRI scan may not change the medical plan, so tests may be unnecessary. An MRI scan or x-ray is usually ordered if there is a plan to do a procedure or surgery based on the result of the images. Studies of medical imaging have demonstrated that MRI scan and x-ray may be too sensitive. They can often show abnormalities that are not truly significant, such as degenerated discs in individuals who do not have symptoms. An improper medical test can lead to improper treatment and can greatly increase medical costs. It is important for such tests to be ordered appropriately.
Tests may include:
—CT scans may show disc herniations as well as tumors and other lesions.
It is more sensitive than x-ray.
—An MRI scan can show if a disc has herniated, and if there are signs of scar tissue around a nerve root. The test can detect other abnormalities, such as bony spurs pressing on a nerve root and tumors.
It is more sensitive than a CT scan.
—Blood tests may include a complete blood count and sedimentation rate. Blood tests may be ordered to check for signs of infection, metabolic disease, or inflammation.
—These tests check for urinary infection or blood in the urine.
—To determine if the nerve going to a muscle is functioning normally or if there may be pressure on it.
It is often performed in conjunction with a nerve conduction study.
—X-rays are then taken to see how the dye lines the space in the spinal canal and if there are disc herniations or other lesions. This test may be ordered before performing back surgery.
—If imaging studies determine that the cause of your back pain appears to be the result of a tumor, your physician may take a piece of the tumor (a biopsy). This will help determine what kind it is and how best to treat it.
Acute low back pain. EBSCO DynaMed Plus website. Available at:
Updated August 12, 2016. Accessed October 4, 2016.
Boden SD, Davis DO, et al. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J.
Bone and Joint Surg. 72-A:403-408, March 1990.
Boden SD. The use of radiographic imaging studies in the evaluation of patients who have degenerative disorders of the lumbar spine.
Journal of Bone & Joint Surgery—American Volume. 78(1):114-24, 1996 Jan.
Bogduk N. Degenerative joint disease of the spine.
Radiol Clin North Am. 2012;15(4):613-28.
Chou R, Qaseem A, Owens DK, et al. Diagnostic Imaging for low back pain: Advice for high value health care from the American College of Physicians. Ann Intern Med. 2011;154(3):181-189.
Chronic low back pain. EBSCO DynaMed Plus website. Available at:
http://www.dynamed.com/topics/dmp~AN~T116935/Chronic-low-back-pain Updated August 18, 2016. Accessed October 4, 2016.
Jensen MC, Brant-Zawadzki MN, et al. Magnetic resonance imaging of the lumbar spine in people without back pain.
N Engl J Med. 1994;331:69-73.
Low back pain. American Academy of Orthopaedic Surgeons website. Available at:
http://orthoinfo.aaos.org/topic.cfm?topic=a00311. Updated December 2013. Accessed December 15, 2015.
National Institute of Neurological Disorders and Stroke
website. Available at:
Updated November 3, 2015. Accessed December 16, 2015.
Russo RB. Diagnosis of low back pain: role of imaging studies.
Clinics in Occupational & Environmental Medicine.
5(3):571-89, vi, 2006.
Sciatica. EBSCO DynaMed Plus website. Available at:
Updated February 8, 2016. Accessed October 4, 2016.
Zhou Y, Abdi S. Diagnosis and minimally invasive treatment of lumbar discogenic pain--a review of the literature.
Clinical Journal of Pain. 22(5):468-81, 2006 Jun.