We are Water!
Between the bones, or vertebrae, in your spine lives a little disc that has a big responsibility. This disc works to help absorb shock on your spine and also helps to shield your back from the damage of daily use leading to wear and tear.
You can think about this disc like a little jelly donut. It has a tough but flexible outer layer surrounding a squishy, jelly-like center. The jelly, officially called the nucleus pulposus, is made up of – guess what? Water.
Your discs are made to lose water and then rehydrate, because the movement of your spine and gravity causes water to flow through your spine and be reabsorbed by the discs. If not enough water is available for the discs to absorb what they’ve lost, then it can’t function as it was meant to. Since most of the jelly inside the discs in your spine is made of water, it will shrink if not hydrated adequately. When it shrinks it will cause the outer layer to take on more of the stress of absorbing shock and supporting your spine.
Eventually, this can cause swelling, pain and even a bulge or rupture in the disc's outer shell – and believe me when I say that can be quite uncomfortable.