Nonspecific pain in any part of the body means the cause of the pain is unknown. The patient may be able to describe how often and how much it hurts. They may even be able to show the doctor where it hurts. But there's no clear soft tissue or bony structure known to be causing the symptoms.

Nonspecific low back pain (LBP) is actually the most common diagnosis for LBP. Most of the time there's no way to tell what's wrong. Even with X-rays or MRIs the real cause may remain unknown. It's easy to assume that a finding on imaging studies is the problem but many people without symptoms have the same kind of changes.

Until a better way of identifying or classifying back pain comes along, doctors will probably have to continue using "specific" versus "nonspecific" to describe the problem.