Your spine is made up of 33 vertebrae that are stacked on top of one another. Between each of these vertebrae is a rubbery piece of cartilage called an “intervertebral disc.” Imagine the disc as a tire, with gelatin filling the hole in the tire. The tire is called the “annulus,” and the gelatin is called the “nucleus.” When we’re young—under 30 years of age—the disc is made mostly of gelatin. As we age, and sometimes with injury or excessive wear and tear, we start to lose some of that gelatin, and the volume of the disc decreases, resulting in less space between the vertebrae. The disc becomes flatter and less flexible, leaving less space between each set of vertebrae. Sometimes bone spurs form in response to this degeneration of the disc, making the spine stiff. When the rough surfaces of the vertebral joints rub together, pain and inflammation may result. Nerves may become irritated or compressed.
Disc degeneration might occur throughout several regions of the spine, or it might be limited to one disc. When it’s part of the natural aging process, the degeneration does not always lead to pain. For some people, however, it can cause a great deal of pain and disability.