Degenerative Disc Disease
john miller physiotherapist
Article by John Miller
What is Degenerative Disc Disease?
degenerative disc disease
Degenerative Disc Disease
Your intervertebral discs are the shock-absorbing rings that sit between the bony vertebral bodies in your spine. They are made up of two main parts; the annulus and the nucleus. The nucleus refers to the inner, jelly-like section of the disc which can change shape to adapt to different loads placed on the spine. This is very important for shock absorption between spinal segments, as well as ensuring there is enough room between each vertebrae for movement of the spine and for major nerves to pass in and out of the spinal canal.
The annulus is the outer component of the intervertebral disc, and is made up of dense fibrocartilage. This tough layer encases the fluid sac and plays a vital role in controlling the amount of movement the nucleus is allowed.
At birth, your intervertebral discs are made up of up to 80% water. As we age however, the discs “dry out” leading to poorer shock absorption ability and increased risk of small tears developing in the outer annulus layer. This is a normal part of the aging process and, in many cases, is not painful.
This degenerative process affecting your discs is known as degenerative disc disease.
Risk Factors for Degenerative Disc Disease
Although degenerative disc disease is a common part of ageing life, there are some factors which have been linked with higher incidence of disc degeneration. These often relate to increased forces travelling through the spine, and include:
Carrying excess body weight
Family history of early disc degeneration
Careers involving heavy manual labour or vibrations
Active lifestyle
Conditions affecting the biomechanics of the spine, such as osteoarthritis and scoliosis
Symptoms of Degenerative Disc Disease
Although degenerative disc disease can pass by unnoticed, an ageing disc can sometimes be very painful. It is thought that this pain originates from the inflammation and/or micro-instability surrounding the affected discs, as well as the muscle spasm that occurs in the area as a natural response to the altered biomechanics of the spine.
The close relationship between your intervertebral discs and the spinal nerves also means that as the disc degenerates and the space between the vertebrae decreases, there is greater risk of irritation of nerves entering and leaving the spinal canal.
Common symptoms of degenerative disc disease include:
Lower back pain, which may travel into the buttocks, hips and legs
Pain that is aggravated by prolonged sitting or activities which load the intervertebral discs such as bending, lifting or twisting
Relief of pain by changing positions, standing up, lying down, or walking
Pins and needles or numbness down the leg may also occur when the spinal nerves around the affected disc become sensitive or irritated
It is important to note that the symptoms and amount of pain experienced varies from person to person, and is not indicative of the amount of degeneration or injury.