According to the American Chiropractic Association, back pain is one the most common reasons Americans miss work and the second leading reason they visit a doctor. One very common cause of back pain is the breakdown and herniation of a spinal disc. When a disc dries out and cracks, it bulges out beyond its normal confines and puts pressure on nearby nerves. This causes muscle spasms and leads to inflammation in the area. Pain caused by a disc is referred to as discogenic back pain. Several different types of discogenic pain occur.
Disc Herniation
Spinal discs are located between each of the vertebra and are responsible for cushioning and shock absorption. Discs have two components: a set of tough outer rings called the annulus contains the soft, jelly-like center, called the nucleus. When the annulus cracks, it allows the nucleus to bulge or herniate out into the spinal canal and put pressure directly on the delicate spinal nerves. This pressure leads to symptoms including pain that may radiate along the course of a nerve, muscle weakness, spasm and loss of sensation, according to the National Institutes of Health. Most people will recover with conservative treatment, but occasionally surgery is necessary. This direct pressure on a nerve is one type of discogenic back pain.
Internal Disc Disruption
Another type of discogenic pain is internal disc disruption, or IDD. The mechanics of this condition are very similar to what occurs with direct pressure on a nerve, except that the pain does not come from the spinal nerves that are receiving pressure. The pain comes from nerves within the disc itself. There are pain generating nerves in the outermost layers of the annulus. When the annulus cracks and allows the nucleus to push into the annulus, chemicals called proteoglycans irritate the sensitive nerves in the annulus and cause inflammation and pain, according to Spine Universe. The main difference between a normal disc herniation and IDD is that when IDD occurs, the tear in the annulus is not complete and the nucleus is still contained within the annulus. This condition is also known as a torn disc, or subligamentous herniation.
Spasm
The type of injuries or conditions that lead to disc herniation or breakdown also cause tremendous stress on the surrounding muscles. According to Cedars-Sinai, muscles that are overstressed become inflamed and begin to spasm. A spasm is an involuntary contraction of the muscle that may be intermittent or persistent. These muscle spasms may not necessarily be painful in and of themselves, but can aggravate a torn or herniated disc, causing greater inflammation and greater pain.
