3 Reasons Why your Discs may be Causing Your Back Pain

If you're one of the 60-80% of people who will at some point experience back pain, you may find that one or more of your spinal discs is responsible. Spinal disc pain is common in people with back troubles, affecting about 40% of cases.

The intervertebral disc is one of a number of spinal structures doctors and pain experts call "pain generators." Essentially, pain generators are places in the body where abnormal physiological activity gives rise to pain.

When it comes to spinal intervertebral discs as pain generators, 3 main types of abnormal activity, are possible.

Disc Pain that Comes from the Outside

The first occurs when the disc structure is injured from the outside. Classic examples of this type include disc herniation and annular tear. A disc herniation occurs when the soft, jelly like substance located on the inside of the disc bulges or breaks through the strong outer binding (which is made of tough fibers.)  Pain may occur if that substance, called the nucleus pulposus, comes into contact with (and irritates) a spinal nerve root. An annular tear is a fraying of the tough outer fibers that surround the nucleus pulposus.

One common way people herniate their discs is by lifting heavy objects with a rounded spine (i.e. not bending the knees to lift) and twisting the spine at the same time. Spinal disc herniation often occurs in younger adults between the ages of 18 and 35 when the water content of the disc is still high.


Related:  How to Lift Heavy Objects without Straining Your Back

How Do Discs Feel Pain?

According to Dr. Alexander Vaccaro, Professor of Orthopedic Surgery at Thomas Jefferson University and Rothman Institute in Philadelphia, PA, the annulus fibrosus contains nerve fibers which are capable of communicating pain.

Vaccaro notes that normal nerve fibers capable of transmitting pain signals have not been found more deeply in the disc. But a variety of substances capable of bringing about pain have. These substances include Prostglandins, lactic acid and substance P. And, as discs degenerate, says Vaccaro, nerve ingrowth has been observed - both in the internal-most fibers of the annulus, and in the nucleus. Vaccaro reports that this extra nerve growth located inside a degenerating disc may significantly add to your pain.

Internal Disc Disruption

The second type of abnormal activity in a disc that can lead to pain is due to a condition known as internal disc disruption, or IDD for short. Note that IDD is not the same as degenerative disc disease. While degenerative disc disease is due to normal age-related changes that go on in the spine, IDD involves internal changes associated with degeneration of the nucleus pulposus. (Remember, the nucleus pulposus is that soft jelly-like substance located in the center of the disc.) This particular type of degeneration can extend to the innermost fibers of the annulus that surrounds the nucleus.

Unlike disc herniation and annular tear,  IDD related degenerative changes do not reach the outer fibers of the annulus.

IDD related pain may be tricky to diagnose because while your disc may seem perfectly normal on the outside, degeneration may be occurring inside the nucleus and annulus, according to the Physio-pedia website.

Related  Discogenic Pain

Whether your disc pain comes from outer impact or internal changes, most likely forward and backward movement of your spine (called flexion and extension, respectively) will bring on the greatest pain, according to Sizer, et. al in their 2001 study entitled, "Pain Generators of the Lumbar Spine."

A third reason your discs may cause you pain is infection, which is beyond the scope of this article.


Cervical Disc Disease. http://emedicine.medscape.com/article/305720-overview. Accessed May 10, 2015.

Internal disc disruption - Physiopedia, universal access to physiotherapy knowledge. http://www.physio-pedia.com/Internal_disc_disruption. Accessed May 8, 2015.

Simon, J., MD, McAuliffe, M., MD, Shamin, F., MD, Vuong, N., MD, Tahaei, A., MD. Discogenic Low Back Pain. Phys Med Rehabil Clin N Am 2014. Accessed May 2015

Sizer PS, Phelps V, Azevedo E. Disc related and non-disc related disorders of the thoracic spine. Pain Pract. 2001;1(2):136-149. doi:10.1046/j.1533-2500.2001.01015.x.

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