Diagnosis of lower back pain involves five to six steps. You will be first asked to tell your symptoms. After having a full discussion about the various signs you mention, your doctor will go through your medical history to check out any other illness or chronic problems you may have. Next, your doctor will examine your back, giving pressure with different hands on the areas to find out where you feel the pain more. He may also use some medical tongs to test the intensity of the pain you get when you are given pressure.
After examining for the pain in the back, the doctor moves to test the functions of nerves in your legs to find out whether the nerves are profoundly affected due to the back pain. Based on the medical opinion from all the above examinations, the doctor will suggest some imaging tests be done. First, he will go for X-rays. Though he can have only visual ideas about your bones, it will help him to find out what apparent cause produces back pain for you.
If he wants a further diagnosis, he will ask for an MRI, which will give a clear image of various internal tissues, like muscles, nerves, and discs. After this test, if your doctor suspects that you may have a bone problem, he may suggest you go for a CT scan. This scan will help your doctor to identify the actual issue of your bone that causes pain for you, and to rule out other causes, such as bone cancer or infection in bones.
As the next step, you may be asked to do the bone density test to test the level of calcium in your bone and to find out whether your bone has become brittle and fragile due to loss of some tissues, resulting in thinning of the bones. It is not that osteoporosis may be the reason for the back pain, but to find out if the pain is due to any fractures in the spine due to osteoporosis. From the results of all these tests, your doctor will identify the reason for your back pain and will start the medication to help you get out of the pain.