Degenerative disc disease is a common condition affecting the spine, frequently associated with the natural aging process. It involves changes to the flexible cushions located between the vertebrae, which are the bones that make up the spinal column. This article explores what degenerative disc disease is, how prevalent it is, the factors that contribute to its development, and common indicators that it might be present.
What is Degenerative Disc Disease?
Intervertebral discs are specialized structures positioned between adjacent vertebrae in the human spine. Each disc consists of a tough, fibrous outer ring called the annulus fibrosus and a gel-like inner core known as the nucleus pulposus.
These discs function as natural shock absorbers, cushioning the spine and facilitating its flexibility. They also support the body’s weight by distributing pressure evenly across the vertebral column. Over time, these discs undergo changes that are part of the normal aging process.
The nucleus pulposus, which is largely composed of water, can begin to lose its hydration, causing the disc to become thinner and less pliable. Additionally, minor injuries or repeated stress can lead to small tears or cracks in the annulus fibrosus. These structural alterations reduce the disc’s ability to absorb shock effectively and can contribute to spinal discomfort.
Degenerative disc disease is not a disease in the traditional sense, but rather a descriptive term for these age-related changes within the spinal discs. While everyone experiences some degree of disc degeneration with age, not everyone develops symptoms or pain. The presence of these changes on imaging does not automatically indicate issues.
How Common is Degenerative Disc Disease?
Degenerative disc disease is common, with its prevalence increasing with age. Imaging studies reveal that disc degeneration is present in a substantial portion of the population, even in individuals who do not experience back pain.
For instance, approximately 37% of 20-year-olds already show signs of disc degeneration on imaging. The numbers continue to rise steadily through adulthood. By age 50, around 80% of people exhibit disc degeneration on imaging scans. This prevalence climbs even higher, reaching approximately 96% in individuals aged 80 years.
One study found that about one-third of people aged 40-59 years have imaging evidence of moderate to severe degenerative disc disease. These findings highlight that disc degeneration is an expected part of the aging spine rather than an unusual occurrence.
While disc degeneration is nearly universal in older adults, the presence of symptoms can vary. A systematic review indicated that imaging evidence of disc degeneration is more prevalent in adults with low back pain compared to those without symptoms. Research suggests that spinal degenerative conditions progress more frequently in women, and the overall prevalence of diagnosed degenerative disc disease tends to be higher for females.
Factors Influencing Its Occurrence
Several factors contribute to degenerative disc disease. Age is the primary non-modifiable factor, as wear and tear on spinal discs accumulates over a lifetime.
Genetic predisposition also plays a role; individuals with a family history of back pain or degenerative disc disease have a higher likelihood of developing the condition. Lifestyle and environmental factors also influence disc degeneration.
Smoking reduces blood supply and nutrient flow to the discs, accelerating dehydration and structural damage. Obesity places constant pressure on spinal discs, especially in the lower back, which can hasten degeneration. Occupations involving heavy lifting, repetitive bending, or twisting movements can put increased stress on the discs, leading to faster wear.
Conversely, a sedentary lifestyle can weaken back muscles, providing less support for the spine and potentially increasing stress on the discs. Acute injuries or trauma to the spine can initiate or accelerate the degenerative process. While some factors are beyond control, managing modifiable risks can contribute to spinal health.
Recognizing Potential Signs
Although many individuals have disc degeneration without discomfort, certain signs and symptoms can emerge when the condition becomes problematic. Common indicators involve localized back or neck pain, depending on the affected spinal region.
Pain can range from mild to severe and may occur in intermittent bouts, lasting weeks or months. The pain often worsens with activities that place increased load or stress on the discs, such as prolonged sitting, bending, lifting, or twisting movements.
Conversely, relief may be found when walking, frequently changing positions, or lying down, as these actions can reduce pressure on the affected discs. When disc degeneration affects nerve roots, symptoms can include pain radiating to other areas, down the buttocks and legs (sciatica) or into the arms and hands. Numbness, tingling, or weakness in the extremities may also be experienced.