The discs consist of 80% fluid (mainly water) while the rest of 20% consists of proteins and solid fibers. Furthermore, they have two components, namely the tougher external section referred to as annulus fibrosus and the softer, squishy internal section known as nucleus pulposus. Evidently, the shock absorbing capabilities of these intervertebral discs are provided by the fluidic nucleus that, over the course of time, degenerates at faster or slower rates.
However, in the internal section of the discs – the nucleus pulposus – there are absolutely no nerve endings. This entails that the potential damage to the fluidic section of the disc will not generate painful sensations, irrespective of the state of degeneration. At the same time, there are not blood vessels traversing the inner section of the discs, which means that the self-repair capabilities of the nucleus are virtually inexistent.
In regards to the external section of the disc, the annulus includes both nerve endings and blood vessels, which obviously means the exact opposite:
Although the possibility of painful sensations being associated with the deterioration of the external disc section does exist, it is not mandatory. The symptomatology of the condition varies significantly from patient to patient and, in certain cases, there are absolutely no indicators of its existence prior to a medical examination.
Degenerative disc disease or DDD for short constitutes a physical condition in which the intervertebral discs begin to erode and eventually break. In order to explain this condition, it is necessary to point out that the human spinal column is essentially a row of connected bones and, in between each of these bones, there is a disc filled with a gel-like tissue that perform several functions such as: