In general, herniated discs are found in younger patients. When we are born, our discs are 70 to 80 percent water. As we age, we lose some of this water in a process called desiccation. It is while the discs are at their most water-filled state that we are most vulnerable for herniation of the gel. The disc itself creates height or distance between the vertebral bodies. This height creates tension in the ligaments that hold the vertebrae together. During the day, our discs lose water content and height. As we lose disc height, our spine actually can loosen up due to this loss of tension. This is why you should measure your height first thing in the morning. We all shrink throughout the day!
Our discs actually have two components. One is the soft center called the nucleus pulposus and the other is called the annulus fibrosis, which is the outer circumferential ligament that holds the soft center part inside.
When some of the soft center portion starts to push through the outer ligament it is called a disc herniation. Unfortunately, there is no consistency in how different radiologists describe this. Your report may say that the disc is herniated, bulging, extruded, displaced etc. Don’t worry, it may be exaggerated. In the office we will look together at your disc and see what is happening. A picture is worth a thousand words.
Disc herniations are typically more painful when one is sitting. To fully understand this, you must understand a simple physical principle that was promoted by a physical therapist from New Zealand named Robin McKensie. When we sit, or otherwise bend forward, there is a force created in the disc space that pushes the gel in the center of the disc from front to back. If the disc has gone through the annulus (herniated), this will cause either stress on the annulus or on the adjacent nerve root. It is almost certain that you will experience a herniated disc during your lifetime. Even if you are lucky enough to avoid this, you will certainly know someone else who has experienced it.
Herniated discs are a common finding. MRIs done on asymptomatic patients often show herniated discs. In fact, the majority of herniated discs have no effect. How do we know this? There have been many MRI studies done on asymptomatic patients that show herniated discs. Each decade in your life you will likely accumulate more of these. So the first thing to remember is that if you have a herniated disc on an MRI it not only may mean nothing, it probably means nothing.
Most herniated discs don’t hurt.
The presence of a herniated disc is only relevant when, in the minority of cases, the disc is causing the pain. The majority of patients sent to me because their doctors thought that the herniated disc was the cause of the patient’s pain, has pain from a source other than the herniated disc. As discussed, this is most commonly a non-specific site, but could be the facet joint, the muscles, or the supporting fascia.
It is often hard to know if the disc is causing the pain. This is why surgically treating the herniated disc does not guarantee the back pain will be better. That does not mean that in any given case, surgery will not make the back pain better, but that it is very difficult to predict success. Even, once herniated, a disc does not always need treatment.
The vast majority of disc herniations will resolve themselves with time.