Back pain, especially in the lower back, is a common issue that many people suffer from each and every year. Sometimes, a specific injury can set off this pain, but other times the pain can manifest itself over time. No matter the cause of your pain, many back issues come about due to damage to the discs in the spine. These discs are called intervertebral discs because they sit between each of the bony vertebra. These are a highly important part in the spine as they function as shock absorbers, hold the vertebrae together, and allow for mobility in the back.
What are the different parts of a spinal disc?
Intervertebral discs, also known as spinal discs, are composed of two different parts: a softer inner core and a tough and rigid outer section. These discs are generally about one inch in diameter and have a thickness of about a quarter inch. They are found between each of the vertebrae in the spine and all serve the same functions.
The inner section is called the nucleus pulposus and is composed of a number of fibers that are loosely connected to one another. These fibers are suspended in a gel-like substance made of glycoproteins. This section functions as a shock absorber, keeps the vertebrae from rubbing against one another, and has elastic resistance, making it incompressible. This substance also helps to spread out pressure evenly across the disc, which helps to reduce the chance for high stress compression injuries.
The outer section, called the anulus fibrosus, is cylindrical in shape and is made up of a number of criss-crossing collagen fibers in multiple layers that provide a rigid and durable exterior for the spinal discs. The outer layer utilizes both type I and type II collagen, and type I collagen makes up the outside of the rings to provide extra strength and is built to withstand compression. Besides support, the anulus fibrosus also helps to keep the inner gel contained so that it can continue to act as a bearing for the vertebrae
How does a disc become damaged?
One of the most common ways that discs become damaged is because of disc degeneration, also known as degenerative disc disease. Over time, the intervertebral discs begin to dry out, causing them to become stiff and cracked. When this occurs, the discs are less able to respond to compression.
Herniated discs, also known as slipped or torn discs, are another common spinal disc issue. A herniation can occur due to an injury, heavy lifting, twisting, or just from a specific movement that puts too much pressure on one of the spinal discs. When a disc tear does occur, part of the disc can protrude outwards and the fluid inside the disc can leak out, reducing the padding ability of the disc.
Herniated discs often occur at random times and are generally caused from a specific movement. These injuries are more common as the body ages because disc degeneration can make a slipped disc more likely.
How does a damaged or torn disc cause back pain?
When a spinal disc begins to degenerate and break down, it causes them to become rigid and cracked, which can make certain movements painful. The cracks can allow the internal fluid to leak out, resulting in swelling and tenderness. The leaking fluid also causes the discs to begin to flatten out and shrink, reducing the space between each vertebra. If the vertebrae begin to rub against one another, it can be very painful and can cause bone spurs to grow, resulting in additional discomfort.
In the case of a torn disc, the disc slips out of position. The disc does not physically move as it is fastened to the vertebrae, but instead, the internal fluid can bulge out of alignment. A herniated disc can also cause the fluid inside to leak much more quickly, and the discs can rapidly become compressed. This causes the vertebrae to rub and grind against each other and can result in severe pain.
The protruded portion of the disc can also put pressure directly on the spinal nerve root, which is called a pinched nerve. Pinched nerves most commonly result in symptoms of sciatica, which include tingling, searing, sharp, shooting, or radiating pains in the low back, hips, buttocks, and down the leg into the feet and toes.
The pain associated with a herniated disc is commonly noticed much more in the legs than in the back. Depending on the location of the herniation, the areas where the pain is felt can vary as different nerves affect the front or back of the thighs, the calves, or down into the foot. The pain also generally only affects one side of the body.
Spinal Discs and Back Pain
Back pain can come about from a number of reasons, and many of them can be due to injuries to the discs between the vertebrae in the spine. The most common injuries to intervertebral discs include disc degeneration and herniation, which can occur due to everyday wear and tear or due to a specific motion or exercise. These issues can be quite painful, resulting in swelling, tenderness, and even nerve pain. If these issues do become apparent, it is important to take care of them to prevent them from getting worse and causing further damage to or pain in your spine.