What Causes a Herniated Disc?
Herniated discs are caused when the inner material of a spinal disc bulges through the thicker, outer layer.
Spinal discs, also known as intervertebral cartilage, are essentially cushions that sit between each of the vertebrae of your spine and absorb all the shock that your back takes throughout the day. In a healthy spine, these discs are full of a gelatinous-like substance (known as the nucleus pulposus) which give them their ability to flex and compress. Meanwhile, the rigid outer shell of the disc (known as the annulus) ensures that everything remains contained and provides durability.
A great way to picture a healthy spinal disc is to think of jelly doughnut. The jelly represents the nucleus pulposus and the pastry represents the annulus.
However, as our bodies age and have experienced decades of constant wear and tear, the annulus (outside layer) of the disc naturally begins to weaken, this is commonly known as degenerative disc disease. For many people this organic degeneration isn't a problem and is completely asymptomatic, however in some cases this degeneration can cause the disc to collapse, crack or rupture, causing the nucleus pulposus to extrude outside of the disc, creating a herniation.
A disc can also herniate as a result of a sudden, violent movement — a car accident, for example. Also, any strenuous physical activities that involve pulling, heavy lifting, twisting, or other forms of hard labor, can also lead to herniated discs. In most cases of herniated discs, especially in older patients, this sort of sudden onset is not the case. It’s rare that a sufferer pinpoints the exact cause.
Depending on the location of the ruptured disc, the inner disc material can begin to put pressure on the sensitive nerve roots that exit from the spine. This can cause pain directly in the back or in the location connected to the impacted nerve root.
There are two types of nerve pain caused by herniated discs. The first, mechanical, is caused by a piece of the disc itself compressing the nerve. The second, chemical, is due to chemicals released by damage to the disc that irritates the nerve.
It's important to note that back pain can be a little tricky to self-diagnose. Most pain that occurs in the back is actually the result of strained, pulled or inflamed structures (like muscles or tendons) that support the spine. Pain in these areas can feel like it's emanating from the back when, in reality, it's coming from a different area entirely. One way you can determine the seriousness of your spine pain is to see how conservative treatments like rest, anti-inflammatory medication like ibuprofen, heat therapy and massages help your spine. If your condition improves after a couple of days, it was likely not a symptomatic spinal condition.
In contrast, pain from an acutely herniated disc can cause pain that may not improve with rest and medications. Leg raises are one test specialists frequently use to see if the pain in question is leg pain. In the case of herniated discs between the L4 and L5 vertebra, or between the L5 and S1 vertebra, pain at leg raises were accurate predictors of herniated discs 80% of the time. If you're experiencing daily pain from your spine that is not improving with conservative treatment, it's time to consider visiting a spinal specialist.