Properly diagnosing back pain requires a medical history and a physical examination by a doctor. If necessary, additional tests, such as an x-ray, may be ordered. Your doctor will begin by asking you questions about your back pain, such as if you have fallen recently and if there are certain activities or times of the day when the pain is worse. Make sure to tell your doctor if you or any close family members have experienced any health problems or conditions, as these may help your doctor pinpoint the cause of the pain.
Your doctor may follow these questions by asking you to stand or walk and then checking your reflexes to look for slowed or heightened reflexes, as these may be a sign for nerve problems. Your doctor may check for fibromyalgia by looking for tender points on your back. Your doctor also will likely check your muscle strength and sensation as well as signs of nerve root irritation.
Additional tests used for diagnosis of back pain may include the following:
- X-rays. Your doctor may order an x-ray if he or she suspects that you have a fracture, osteoarthritis or an unaligned spine.
- MRI scan. Your doctor may order an MRI scan if he or she suspects a problem such as an infection, a tumor, inflammation or pressure on a nerve. An MRI scan is needed if your pain lasts longer than three to six weeks or if your doctor feels there may be a need for surgical consultation. Unlike an x-ray, which shows only bony structures throughout the body, an MRI scan produces clear pictures of soft tissues such as ligaments, tendons and blood vessels.
- CT scan. A CT scan allows your doctor a clearer and cleaner view of spinal structures that cannot be seen through a generic x-ray. A computer creates a three-dimensional image and can identify problems such as herniated disks, tumors or spinal stenosis (narrowing of the open spaces in the spine).
- Blood tests. Although blood tests are not common in the diagnosis of back pain, they may be used in specialty cases. A complete blood count (CBC) could be used to point to problems such as infection or inflammation. An erythrocyte sedimentation rate (sed rate) could measure inflammation and infection, which could point to types of arthritis or tumors. A C-reactive protein (CRP) test is another blood test used to measure inflammation and the possibility of arthritis. HLA-B27 is a test to identify a genetic marker in the blood more common in people with ankylosing spondylitis — a form of arthritis affecting the spine and sacroiliac joints.