Herniated Disc Causes

One of the causes of herniated discs is due to the outer wall of the intervertebral disc weakening at a faster rate than it loses its volume of water content in the nucleus of the disc.

At around the time we reach our full height, the vertebrae of the spine is fully developed, and the intervertebral discs between the spinal bones are saucer shaped and fully elevated. These discs are at their full height, and they are flexible enough to bend slightly downward when our spine has to take on and absorb weight, such as when we position ourselves upright, stand, and walk. These discs have two main parts: the outer shell (discus annulus) which is composed of several bands of tough fibrous layers, and the inner core (nucleus fibrosus) of thick jellylike material that gives the disc its pliability. Though the disc does bend and bulge slightly to take on added forces of gravity when we are sitting and standing, the this strong, outer envelop resists letting the disc from bursting or losing its fundamental shape. The volume of the jelly-like interior of the disc changes throughout a 24-hour cycle, losing water when weight is compressed on it, and absorbing water and nutrients when we lie down at night. This is one of the reasons that we are taller when we wake up and shorter after a long day's activities.



As we get older, two things happen to the disc. Over time the discs lose their ability to absorb water and nutrients, causing them to shrink over time. Also, the outer solid layer of the disc begins weaken, either as a result of the loss of water in it's interior, or due to it's own age related wear and tear.

These two degenerative changes that occur in the discs do not necessarily lead to back pain, and they do not necessarily lead to herniated discs. The drying out process that the disc undergoes towards it's nucleus may also help the spine to avoid back pain if the rate that it loses water is similar to the rate at which the annulus weakens. Remember that the nerve fibers that supply the intervertebral discs travel only to the outer envelope (annulus), and that we are not directly affected by the loss of volume water in its nucleus - in terms of pain. In an ideal scenario, as the liquid content of the disc decreases, the nucleus will exert less force on the fibers of the annulus. Think of picking up a brand new balloon, and then fully inflating it. As you fill the balloon with more and more air, it begins to expand, and the rubber sides begin to become very firm and tight. Since this balloon is brand new, its rubber outer surface can withstand a lot of pressure pushing against it. But if you leave a blown up balloon for a few days, a bit of air will usually leak out. The pressure on the sides of the balloon will diminish as the air is let out, and they will not give away as easily as if there is a weakness in one or two spots.

Herniated disc causes. If the outer wall of the disc weakens at a rate that is much faster than the rate at which the nucleus loses water due to age, the pressure exerted against if may make it prone to bulging out or becoming torn. This is one of the causes of a herniated disc.