(RxWiki News) Even a sneeze can rupture a disc in your back. Here’s what you need to know about a herniated disc.

About 10% of people have symptoms from a herniated disc at some point in their lives. Autopsy studies reveal, however, that most people actually have a herniated disc but never get any symptoms.

Over the years, the demand of supporting the body’s weight causes the outer layer of the disc to weaken, become thinner, and develop microscopic tears. At the same time, the center of the disc slowly loses its water content and it becomes progressively drier.

• These changes make the disc susceptible to herniation (protrusion).
• Mild trauma from lifting an object or even sneezing can cause the center of the disc to bulge through the weakened outer layer.

Symptoms often occur when the protruding disc presses on one or more of the spinal nerves emerging from the spinal column.

• In some people, the disc presses on the spinal cord itself or on the cauda equina (bundle of nerve roots at the bottom of the spinal cord).
• This causes pain in the back and in the part of the body served by the compressed and inflamed nerve. Disc fragments can also break free.
• This is a condition known as sequestration.
• Any disc can herniate, but about 90% to 95% of cases occur in the two lowest discs, which bear the greatest weight.

When a disc herniates, both the site and extent of the rupture determine the location and severity of the symptoms. For example, a herniated lumbar disc may cause pain, numbness, or weakness in one leg (sciatica). A herniated cervical disc may produce similar symptoms in one arm or hand (less commonly on both sides).

• Pain due to a herniated disc usually strikes suddenly.
• The person may “feel something snap” before the pain begins.
• The pain may start as a mild tingling or a “pins and needles” sensation before increasing in severity.

If the herniated disc compresses a lumbar nerve root, pain later radiates into a specific area of one leg.

• A decrease in back pain may be accompanied by increasingly severe pain, numbness, and weakness in one leg, along with changes in reflexes.
• In fact, a herniated lumbar disc is the most common cause of sciatica (a pain that radiates into the buttocks, down the thighs, into the calves, and often into the feet; the pain is caused by irritation of the sciatic nerve).

If a ruptured disc compresses nerves in the neck, pain may radiate down the arms and be accompanied by weakness and numbness in the arms and hands.

Each intervertebral disc is composed of two distinct regions:

• A tough, fibrous outer ring made up of many overlapping layers of collagen fibers (called the annulus fibrosus)
• A soft, gel-like core (the nucleus pulposus)

In a normal, healthy disc, these tissues contribute to the remarkable flexibility of the spine:

• As the body moves, the annular fibers expand and contract, while the gel-like nucleus changes shape.
• Although each individual disc can bend only to a limited degree, their combined flexibility throughout the spine provides a great range of motion.

As we age, however, the discs gradually lose their resiliency, becoming drier and more brittle. These changes make the disc more vulnerable to herniation. This is commonly known as a slipped disk.

Herniation may produce only local back pain, or pain may radiate down the path of a spinal nerve if the nerve is compressed by the protruding disc. There are varying degrees of herniation, ranging from mild to severe.