A spinal ‘disk’ is the rubbery, hockey puck-shaped structure of the spine that separates the vertebrae from each other, adding flexibility to the spine. Disks are made of connective tissues, water, and fat, but they have no nerves or blood vessels. Spinal disks are the spine’s shock absorbers, and they can wear out. As you stand and sit during the day, the water is squeezed out of the disk by gravity and replenished when you sleep, but as you age, the overall water content diminishes, which is why you generally become shorter with age. Degenerative disk disease is a change in the spinal disks that results in their loss of elasticity and volume, causing a narrowing of the space between the vertebrae. It’s one of the most common and severe causes of lower back pain. Disks may be weakened by injury, disease, or arthritis, in addition to the aging process. When a disk has been weakened, the bones of the spine may come into contact with one another, causing pain, stiffness, and a weak back. Treatment may include medication, special exercises, or surgery. If you’re experiencing any of these symptoms, contact a health care professional for an accurate diagnosis and suggestions for treatment.