Scientists who study this problem suspect the cause of pain is multifactorial. This means there isn't a single cause but rather, many factors contributing to back pain.

There may be specific anatomical reasons. Social and psychologic variables are often part of the picture. Pain generators from anywhere in the spine can be activated when there is an uneven load, instability, or degeneration from the aging process.

Biologic research has shown that degenerative disc disease can irritate pain fibers within the disc itself. In other words, the disc sets itself up for a painful response to its own demise.

And patients who have had a spinal fusion can still have pain, so there's some thinking that the source of the pain isn't even in the spine. Research is ongoing to help answer some of these questions -- and especially to identify the source of back pain. You aren't alone in wondering what's going on.