I have lumbago.

Back pain: There are many causes of back pain. Watch out if fever is associated with this or if you have had recent weight loss. Go see a doctor to have this evaluated. Usually pain meds and physical therapy and resuming normal activity help with back paun.

Back pain: Most of the lower back is made up from muscles that attach to, and surround, the spine. The vertebrae are roughly circular and between each vertebra is a disc. The discs between the vertebrae are a combination of a strong fibrous outer layer and a softer, gel-like centre. http://patient.info/health/nonspecific-lower-back-pain-in-adults