Slip disc: Rupturing of the tissue that separates the vertebral bones of the spinal column.
The center of the disc, which is called the nucleus, is soft, springy and receives the shock of standing, walking, running, etc. The outer ring of the disc, which is called the annulus (Latin for ring), provides structure and strength to the disc. The annulus consists of a complex series of interwoven layers of fibrous tissue that hold the nucleus in place.
A slipped disc is also known as a herniated disc. The term "slipped disc" comes from the action of the nuclear tissue when it is forced from the center of the disc. The nuclear tissue located in the center of the disc can be placed under so much pressure that it can cause the annulus to rupture. When a disc herniates or ruptures, it may create pressure against one or more of the spinal nerves which can cause pain, weakness or numbness in the area of the body served by those nerves. Other names for slipped (herniated) discs are prolapsed and ruptured discs.
What Is Slipped Disc (Herniated Disc)?
The discs are protective shock-absorbing pads between the bones of the spine (vertebrae). The discs of the spine are also referred to as intervertebral discs. Although they do not actually "slip," a disc may bulge, split, or rupture. This can cause the disc cartilage and nearby tissue to fail (herniate), allowing the inner gel portion of the disc to escape into the surrounding tissue. This protruding, jelly-like substance can place pressure on the spinal cord or on an adjacent nerve to cause symptoms of pain, numbness, or weakness either around the damaged disc or anywhere along the area supplied by that nerve.
Many people experience no symptoms from a herniated disc, and the majority of people who have herniated discs do not need surgery.
The layman's term "slipped disc" is, therefore, a misnomer and actually refers to a condition whereby portions of an abnormal, injured, or degenerated disc have protruded against adjacent nerve tissues. This condition is also known as a slipped disk, herniated disc, ruptured disc, or prolapsed disc. The most frequently affected area is in the low back, but any disc can rupture, including those in the neck.
Slipped Disc - Symptoms, Causes, and Treatment
Understanding the spine
The spine is made up of many bones called vertebrae. These are roughly circular and between each vertebra is a 'disc'. The discs are made of strong 'rubber-like' tissue, which allows the spine to be fairly flexible. A disc has a stronger fibrous outer part, and a softer jelly-like middle part called the nucleus pulposus.
The spine protects the spinal cord, which contains the nerves that come from the brain. Nerves from the spinal cord come out from between the vertebrae to take and receive messages to various parts of the body. Strong ligaments attach to the vertebrae. These give extra support and strength to the spine. Various muscles also surround and are attached to various parts of the spine.
What is a prolapsed disc?
When you have a prolapsed disc (commonly called a 'slipped disc'). A disc does not actually 'slip'. What happens is that part of the inner softer part of the disc (the nucleus purposes) bulges out through a weakness in the outer part of the disc. A prolapsed disc is sometimes called herniated disc. The bulging disc may press on nearby structures such as a nerve coming from the spinal cord. Some inflammation also develops around the prolapsed part of the disc.
Any disc in the spine can prolapse. However, most prolapsed discs occur in the lumbar part of the spine (lower back). The size of the prolapse can vary. As a rule, the larger the prolapse, the more severe the symptoms are likely to be.
Who gets a prolapsed disc?
It is not clear why some people develop a prolapsed disc and not others, even when they do the same job or lift the same sort of objects. It seems that some people may have a weakness in the outer part of the affected disc. Various things may trigger the inner softer part of the disc to prolapse out through the weakened outer part of the disc. For example, sneezing, awkward bending, or heavy lifting in an awkward position may cause some extra pressure on the disc. In people with a weakness in a disc this may be sufficient to cause a prolapse. Factors that may increase the risk of developing a prolapsed disc include: a job involving lots of liftin, a job involving lots of sitting (especially driving), weight-bearing sports (weight lifting etc), smoking, obesity and increasing age (a disc is more likely to develop a weakness with increasing age).