Low Back Pain and Sciatica Diagnosis
Your healthcare provider will ask about your symptoms and medical history. A physical exam will be done. In particular, your back, hips, and legs and will be tested for strength, flexibility, sensation, and reflexes.
Often, patients with pain may feel an urgent need to have a medical test. It is important to understand that medical tests are not routinely required for back pain and sciatica. Most episodes of acute back pain resolve on their own over several weeks, especially with some natural treatments. In these cases, the information from an x-ray or MRI may not change the medical plan, and so these tests may be unnecessary. An MRI 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 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 even 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:
- X-ray—This test uses radiation to take a picture of structures inside the body, especially bones. Back x-rays may show signs of arthritis , degenerative disk disease , osteoporosis , or a tumor.
- CT scan —This type of x-ray uses a computer to generate images of structures inside the body. CT scans may show disc herniations as well as tumors and other lesions.
- MRI scan —This test uses a strong magnetic field and radio waves to take pictures of structures inside the body. An MRI 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.
- Blood tests—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.
- Urine test—These tests check for urinary infection or blood in the urine.
- Nerve conduction study—In this test, an electrical current is passed through a nerve to determine the health or disease of that nerve.
- Electromyography—This test measures the electrical activity of muscle by placing needle electrodes into the muscle. By doing this the doctor can determine if the nerve going to that muscle is functioning normally or if there may be pressure on it.
- Myelography—In this test, a special dye is injected into the spinal canal. X-rays are then taken to see how the dye lines the space in the spinal canal and see if there are disc herniations or other lesions. This test may be ordered before performing back surgery.
- Biopsy—If the cause of your back pain, based on the imaging studies, appears to be the result of a tumor, your physician my take a piece of the tumor (a biopsy) to determine what kind it is and how best to treat it.
Lastly, perhaps the best way to assess how well a treatment is affecting pain is to as the patient how much their level of pain as gone down since the beginning of a certain treatment. Self-reflection like this can be extremely useful and perhaps more empowering than any of the tests written above.
Boden SD, Davis DO, Dina TS, Patronas NJ, and Wiesel SW. 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.
Conn's Current Therapy 2001. 53rd edition. W.B. Saunders Company; 2001.
Jensen MC, Brant-Zawadzki MN, Obuchowski N, Modic MT, Malkasian D, Ross JS. Magnetic resonance imaging of the lumbar spine in people without back pain.
N Engl J Med. 1994;331:69-73.
Pain. National Institute of Neurological Disorders and Stroke website. Available at:
. Accessed October 27, 2008.
Russo RB. Diagnosis of low back pain: role of imaging studies.
Clinics in Occupational & Environmental Medicine.5(3):571-89, vi, 2006.
Textbook of Primary Care Medicine. 3rd edition. Mosby, Inc.; 2001.
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.