What is a Herniated Disc?
A herniated disc is when The Anulus Fibrosis (outer rim) is torn, ruptured or damaged and the Nucleus pulposus (inner gel-like sack) can come through the ruptured park of the Anulus.
Many people suffer from herniated discs, It is helpful to have an understanding of the anatomy and why a herniated disc is painful.
What is a Herniated Disc?
A herniated disc is when the Anulus Fibrosis (outer rim) is torn, ruptured or damaged and the Nucleus pulposus (inner gel-like sack) can come through the ruptured park of the Anulus.
As you can see in this image the disc on the left is a healthy disc without any rupture, bulge or degeneration, the disc on the right shows the herniation, notice how the anulus fibres are torn and the nucleus has secreted through the tear and is now compressing the nerve root. The compression of the nerve root is what usually causes most of the pain
Why is it so painful?
There are two causes of the pain: 1- the compressed (pinched) nerve root, 2- the disc pain.
1- The compressed/ pinched nerve root pain
This is the most common source of the pain and probably the more severe source of pain. The nucleus contains inflammatory proteins, when the nucleus comes through the anulus and compresses the exiting nerve root these inflammatory proteins interact to cause inflammation around the nerve root and ultimately make the nerve very irritated and painful. This type of pain is referred to as radicular pain (nerve root pain) Sciatica is a common type of radicular pain. Pain of this type usually radiates to other parts of your body. If the herniated disc is in your lumbar spine (lower back) it may go down your leg or in the cervical spine (neck) it could be down your arm.
2- Disc Pain
Disc pain Is usually more localised to the back itself. The loss of disc height can cause increased pressure in the joint, the discs nociceptors then send a signal to the central nervous system which is then interpreted as pain. This type of pain is usually called axial pain. It is possible to have both disc and nerve root pain at the same time, in fact, this is very often the case.
Herniated discs are far more common in the Lumbar spine (low back) and the cervical spine (neck). They can occur in the thoracic spine but this is far less common.
SpineHealth.com have a fantastic video that illustrates what happens when you suffer a herniated disc.