Slipped disc and other spinal disc problems
What are spinal disc problems?
Spinal disc problems, such as a slipped disc or degenerative disc disease, can be extremely painful and often need medical treatment.
Spinal discs are supple pads tightly fixed between the vertebrae - the specialised bones that make up the spinal column. Doctors call them intervertebral discs. Each disc is a flat circular capsule about 2.5cm (1in) in diameter and 5mm (1/4in) thick. They have a tough, fibrous outer membrane called the annulus fibrosus. Inside is an elastic core called the nucleus pulposus.
The discs are firmly embedded between the vertebrae and are held in place by the ligaments connecting the spinal bones and the surrounding sheaths of muscle. There is very little, if any, room for discs to slip or move. The points on which the vertebrae actually turn are called facet joints, which stick out like arched wings on either side of the rear part of the vertebrae. These facet joints keep the vertebrae from bending and twisting too far - far enough to damage the spinal cord, the vital network of nerves that runs through the centre of each vertebra.
The disc is sometimes described as a shock absorber for the spine, which makes it sound more flexible or pliable than it really is. While the discs do separate the vertebrae and keep them from rubbing together, they are far from pneumatic or spring-like. In children they are gel- or fluid-filled sacs, but they begin to solidify as part of the normal ageing process. By early adulthood the blood supply to the disc has stopped, the soft inner material has begun to harden and the disc is less elastic. In middle-aged adults the discs are tough and quite unyielding, with the consistency of a piece of hard rubber. These changes related to ageing make the outer protective lining more weak and the discs more prone to injury.
The pain of a slipped (or herniated) disc can be debilitating, and further spinal disc damage may be irreversible.
Under stress, a disc's inner material may swell, pushing through its tough outer membrane. The entire disc becomes distorted. All or part of the core material protrudes through the outer casing at a weak spot, pressing against surrounding nerves. If further activity or injury causes the membrane to rupture or tear, the disc material can injure the spinal cord or the nerves that radiate from it. This causes extreme debilitating pain. It's an unmistakable signal to stop all movement immediately. Further disc damage may be irreversible. In some instances the injured disc itself is the source of pain.
The vast majority of disc injuries occur in the lumbar region of the lower back. Only 10% of these injuries affect the upper spine. However not all slipped discs press on nerves, and it is entirely possible to have deformed discs without any pain or discomfort.
Slipped discs are most common in men and women between 30 and 50 years old, although they also occur in active children and young adults. Older people, whose discs no longer have fluid cores, are much less likely to encounter the problem. People who do regular moderate exercise are much less likely to have disc problems than sedentary adults. People who exercise tend to stay flexible considerably longer.