How does this happen?
As we age, our spine ages, this is a natural process. During this time, the disc, which is the cushion between the bones of your spine, becomes more rigid and dries out. The inner substance of the disc becomes less jelly like. This makes the spine more stiff when it moves. As well, the cushion becomes flatter, which means the walls of the discs bulge out more than usual. Boney changes occur to the spine and the edges of the bone start to develop sharp edges (bone spurs or osteophyte formation) because of the wear and tear on the spine during your life.
All of these changes are normal and usually not painful or symptomatic.
However, these changes can occur at an earlier age, depending on what you have done in your life. Factors like your job (heavy lifting), or sport, or if you have had a fall or motor vehicle accident, will speed up this degenerative process. Degeneration of the disc can occur at one or many levels of your spine.
The process becomes problematic when the flattened discs or the bone spurs pinch or put pressure on the nerves and other structures in the spine, causing pain and loss and movement or function.