A herniated disc is best seen on an MRI. While X-rays will show the position and alignment of the bones in the spine, it takes an MRI to visualize the soft tissue. This includes the tendons, ligaments, muscles and discs.
The discs are the shock absorbers that lie in between the individual vertebrae that comprise the spinal column. The best way to visualize a vertebral disc is to think of a jelly donut. The disc has a flexible outer covering called the annulus fibrosus (the donut part). Inside is a gelatinous substance called the nucleus pulposus (the jelly part). In a healthy disc the nucleus pulposus is contained within the disc and it is moist and fluid as opposed to looking like jelly that has been dried out. Trouble occurs when the nucleus pulposus leaks out from the disc. This is the definition of a herniated disc.
A herniated disc will tend to be painful for several reasons. First, the injury to the disc itself that allows the fluid to leak out is painful. Secondly, if that nucleus pulposus pushes on the nerves that leave the spine or presses on to the spinal cord itself, then symptoms such as pain, tingling or muscle weakness can occur. In the case of herniated discs in the low back, those symptoms can radiate down the legs. In the neck, the symptoms will tend to radiate down the arms.
The body recognizes the nucleus pulposus as a foreign substance. As a result, the system will attack and breakdown the leaking nucleus pulposus. While this also causes pain and inflammation in the area, it does give the body chance to heal the condition.
On the other hand, a bulging disc is more like a bubble in an old tire. It is protruding out but no leak has occurred. This bulge will tend to be painful for reasons similar to above in that the damage to the disc where the bulge is present will often be painful. The bulge can also press on adjacent nerves or the spinal cord.
“Slipped disc” is an inaccurate term used to describe either of these conditions: herniated or bulging disc. In fact, the disc cannot slip as it is firmly attached to the vertebrae above and below.
Both these conditions can respond well to chiropractic care. Part of the treatment entails very gently realigning the vertebrae above and below the disc so as to remove the aberrant forces that may have injured the disc in the first place. In fact, the whole spine needs to be assessed in order to normalize its function. In many cases, a light form of traction known as axial flexion/distraction can do wonders to help open up the disc space and retract the bulge or herniation so as to take pressure off the surrounding tissues and allow the area to heal.
The reality is that disc injuries do take some time to heal – on the order of weeks to a couple months. But with gentle chiropractic care, surgery can be avoided and normal pain-free function restored.