The discs of the spine give our back flexibility and strength. Over time, a disc may bulge or become herniated; we explain the difference between these types of disc injury and tell you when this damage may require medical treatment.
Every time you turn your head to check traffic, lean in to select produce at the farmers market, or swing a golf club, you are relying on the flexibility of your spine. This column of discs stacked between vertebrae works with your muscles to support your body’s weight, and allows you to move through your day.
You have 23 discs between the vertebrae in your spinal column. Each disc has two components: a tough outer covering composed of cartilage and a soft gelatinous inner core—a bit like the composition of a jelly doughnut. As you move, these discs are able to expand and give your spine flexibility. Your discs act primarily as shock absorbers, but they also function as mobile joints and help hold the spine together. Because spinal discs have very few nerve endings and no blood supply, they don’t have a way to repair themselves. As we age, spinal discs naturally become stiffer and degenerate, making them less able to adjust to compression. Trauma to the spine can also cause disc compression injuries.
Some compression injuries are asymptomatic (no symptoms present); others can cause pain, balance problems, or difficulty walking. There are two common types of disc degeneration: bulging discs and herniated discs.
- Bulging discs are more common, and usually do not cause pain. They occur when the disc extends beyond the space it should normally occupy. Think of a bulging disc as a hamburger that’s too big for its bun. Bulging is usually considered part of the normal aging process of the disc.
- A herniated disc—also called a ruptured or slipped disc—occurs when a crack in the tough outer layer of cartilage allows some of the softer inner disc material to protrude out of the disk. Although some herniated disks are painless, this disc injury is more likely to cause pain.
Just because discs deteriorate over time does not mean that the process is painful. Research reported by the National Institutes of Health has shown that 22 to 51 percent of people with MRI findings of a bulging or herniated disc are asymptomatic; the injuries don’t cause pain. These percentages go up as we age; 57 to 80 percent of people who are 60 and older have disc irregularities without experiencing any related discomfort.
If you do experience back pain, an accurate clinical diagnosis begins with a complete physical exam by an orthopedic spine specialist. Exam findings will be correlated with your specific symptoms. Then, a diagnostic test like an MRI or CT scan will be used to confirm the diagnosis. When back pain interferes with your activities or comfort, we are focused on accurately diagnosing the problem and developing a tailored treatment plan that will restore you to the lifestyle you enjoy.