To better understand the causes of cervical spondylosis, it is useful to know more about the structure of your spine.
Cervical spondylosis is caused by age-related wear that affects the spine.
The spine is made up of:
- vertebrae – ridge-shaped sections of bone that make up the structure of the spine (spinal column) and protect the nerves
- discs – discs of tissue that have a tough, flexible outer shell and a softer inside that is the consistency of toothpaste. They lie in between the vertebrae, cushioning and supporting them
- spinal cord – the main bundle of nerves carrying messages up and down your spine, between the brain and the rest of the body
- nerve roots – the beginning sections of the nerves that come out of the spinal cord, exiting through "key holes" all the way down the spine
As you get older, the discs tend to dry out and become susceptible to damage. Your body will also try to compensate for the wearing of the joints by producing small lumps of extra bone to better support your neck and stiffen the spine. These lumps of extra bone are known as bone spurs or osteophytes.
Osteophytes can cause the spine to become too rigid, leading to stiffness and neck pain. The changes in bone structure can also squash nearby nerves and the spinal cord. This tends to be more common in older people.
Other risk factors
Apart from age, there are several other risk factors that may increase the chance of developing cervical spondylitis. These include:
- lack of exercise and obesity
- previous neck or spinal injuries
- previous neck or spinal surgery
- severe arthritis
- a slipped disc (see below)
- repeatedly carrying heavy weights (see below)
A slipped disc, also known as a prolapsed or herniated disc, is when one of the discs that sit between the bones of the spine (the verterbrae) is damaged and presses on the nerves that come out from the spine.
If this soft material presses against a nerve in the neck, it can cause severe pain radiating to the arm (cervical radiculopathy), and can occasionally result in compression of the spinal cord (cervical myelopathy).
Slipped discs are generally seen in younger people and are not as common as the process of osteophyte formation described above.
Read more about slipped discs.
There is some evidence that people who spend a lot of time carrying heavy weights on their head have an increased risk of developing cervical spondylosis.
For example, a study found that rates of cervical spondylosis were much higher than average in Ghanaians, as in Ghana there is a common practice of transporting heavy loads in this manner.