Intervertebral discs are the rubbery pads that fill the space between the bones of the spine, known as vertebrae. They act as shock absorbers for the spine, making the spine more flexible than it would be without the discs. The discs separate the vertebrae and keep them from rubbing together and causing damage to the bones but unfortunately, the discs themselves can suffer injury and cause a multitude of problem and significant pain.
When a there is an injury or a large amount of stress is put on the spine, the inner material of the intervertebral discs may swell, pushing through its tough outer membrane. This can cause the entire disc to become distorted or bulge in spots. Sometimes, all or part of the inside material of the disc may protrude through the outer casing at a weak spot and put pressure on surrounding nerves. If further activity or injury causes the membrane to rupture or tear, the disc material may protrude (herniate) further resulting in extreme pain, weakness and/or numbness. The pain and the trauma can also cause spasms in the back which can further limit movement and activity.
Herniated discs occur most commonly in the lower back and affect men and women ages 30 to 50 the most, but they can also occur in active children and young adults. As we age, the fluid inside the discs diminishes so older adults whose discs no longer have fluid cores are much less likely to encounter problems from herniated discs. Those who exercise regularly are also much less likely to suffer from disc problems than those who are mostly sedentary. People who exercise tend to stay flexible considerably longer. Maintaining a healthy body weight is also important in preventing back problems.
Disc herniation is not the only type of disc problem that occur in the spine. One of the most common disc disorders is known as degenerative disc disease. As a natural result of aging, the intervertebral discs change in composition and size. By adulthood the blood supply to the disc ceases and the soft inner material of the disc begin to harden making the disc less elastic. As time passes, the discs become tougher until they are the consistency of hard rubber. This process makes the outer protective lining of the discs weaker and more prone to injury. There is then a gradual loss of flexibility and the ability of the spine to compensate for extra pressure or injury. Degenerative disc disease can be far more serious in some than in others. Severe cases typically result from a deficiency in collagen, the material that makes up cartilage. It can be aggravated by poor muscle tone, poor posture, and even obesity, all, which put excessive strain on the spine and the ligaments that hold the discs in place.