There are many different terms used to describe spinal disc pathology and associated pain, such as “herniated disc”, “pinched nerve”, and “bulging disc”, and all are used differently by individual healthcare practitioners. Unfortunately, there is no agreement in the healthcare field as to the precise definition of any of these terms. Often the patient hears his or her diagnosis referred to in different terms by different practitioners and is left wondering if there is any consensus on what is wrong.

A herniated disk can affect how you're able to perform everyday tasks and can cause severe pain that influences almost everything you do. You and your doctor will make decisions about how to best treat your herniated disk (herniated disc), sometimes also called herniated disc, ruptured disk or slipped disk. The bones (vertebrae) that form the spine in your back are cushioned by small, spongy discs. When these discs are healthy, they act as shock absorbers for the spine and keep the spine flexible. But when a disc is damaged, it may bulge or break open. This is called a herniated disc. It may also be called a slipped or ruptured disc.

Disks are soft, rubbery pads found between the hard bones (vertebrae) that make up the spinal column. The spinal canal is a hollow space in the middle of the spinal column that contains the spinal cord and other nerve roots. The disks between the vertebrae allow the back to flex or bend. Disks also act as shock absorbers. Disks in the lumbar spine (low back) are composed of a thick outer ring of cartilage (annulus) and an inner gel-like substance (nucleus). In the cervical spine (neck), the disks are similar but smaller in size.

As the spinal disc becomes less elastic, it can rupture. When the disc ruptures, a portion of the spinal disc pushes outside its normal boundary--this is called a herniated disc. When a herniated disc bulges out from between the vertebrae, the spinal nerves and spinal cord can become pinched. There is normally a little extra space around the spinal cord and spinal nerves, but if enough of the herniated disc is pushed out of place, then these structures may be compressed.

When part of a disk presses on a nerve, it can cause pain in both the back and the legs. The location of the pain depends on which disk is weak. How bad the pain is depends on how much of the disk is pressing on the nerve. In most people with herniated disks, the pain spreads over the buttocks and goes down the back of one thigh and into the calf. Some people have pain in both legs. Some people's legs or feet feel numb or tingly.
The pain from a herniated disk is usually worse when you're active and gets better when you're resting. Coughing, sneezing, sitting, driving and bending forward may make the pain worse.

Most herniation takes place in the lower back (lumbar area) of the spine. Lumbar disk herniation occurs 15 times more often than cervical (neck) disk herniation, and it is one of the most common causes of lower back pain. The cervical disks are affected 8% of the time and the upper-to-mid-back (thoracic) disks only 1 - 2% of the time.Nerve roots (large nerves that branch out from the spinal cord) may become compressed resulting in neurological symptoms, such as sensory or motor changes.