Your doctor will ask about your symptoms and your medical history. He or she will examine your back muscles and spine and will move you certain ways to check for pain, muscle tenderness or weakness, stiffness, numbness or abnormal reflexes. For example, if you have a disk problem, you may have pain in your lower back when the doctor raises your straightened leg.
Your symptoms and the physical examination may give your doctor enough information to diagnose the problem. However, with back pain, your doctor may only be able to tell you that the problem is not serious. If your doctor determines that your back pain is caused by muscle strain, obesity, pregnancy or another cause that is not urgent, you may not need any additional tests. However, if he or she suspects a more serious problem involving your vertebrae or spinal nerves, especially if your back pain has lasted longer than 12 weeks, you may need one or more of the following tests:
X-rays of your back
Spinal magnetic resonance imaging (MRI)
Computed tomography (CT) scan
Nerve conduction studies and electromyography to determine whether nerves, muscles or both may be injured
Bone scan, especially if you have a previous history of cancer