(Slipped Disc · Prolapsed Disc · Ruptured Disc)
In this condition factsheet:
The Facts on Herniated Disc
The spine is made up of cylindrical bones called vertebrae. Between the bones of the spine are small discs made of a thick layer of cartilage on the outside and a soft and jelly-like material on the inside. The discs act to absorb shocks caused when the spine moves, and they allow the spine to bend.
The spinal cord is a bundle of nerves running through the canal within the spinal column. It carries messages to and from the brain via nerve roots that branch out to the body along the length of the spinal cord. The nerves exit the spine through small openings on each side; these are called foramens (singular foramen; foramina is also used for the plural), after the Latin word for "window."
If a foramen becomes narrowed by arthritis or a bulging disc, pressure on the nerve can cause numbness and pain, and even muscle weakness if severe enough. A herniated, prolapsed, or ruptured disc happens when the inner material bulges or bursts through the outer lining of cartilage and puts pressure on or damages the spinal nerves or the spinal cord.
Herniated discs can occur in any part of the spine, but they are most common in the neck (cervical spine) and lower back (lumbar section of the spine). Herniated discs are more common in people between 30 and 40 years old, but they can occur at any age. Studies have shown that even some teenagers can be affected.
Causes of Herniated Disc
As we age, the discs in the spine become less flexible, which increases the risk of injury. Other things that can increase the risk of a herniated disc include an injury such as a fall, repeated straining, improper lifting, excessive body weight, and smoking.
When a disc is herniated, the soft material inside the disc comes through the outer lining of cartilage. Normally there is some space between the discs and the spinal column. But, when the herniated disc presses on a spinal nerve, this leads to symptoms of pain, numbness, and weakness.
Symptoms and Complications of Herniated Disc
Not all people with a herniated disc have symptoms. But when a herniated disc presses on spinal nerves, symptoms can include pain, loss of feeling, tingling, or muscle weakness. The amount of pressure the herniated disc puts on the spinal nerves determines how bad the symptoms will be. Coughing, laughing, sneezing, urinating, or straining while defecating make the pain of a herniated disc worse.
Most herniated discs are in the lower back and cause back and leg pain. Intense pain that radiates down from the disc through the buttocks and down the leg to the foot is called sciatica. Intense pain below the knee is usually a sign of a herniated disc, since other back conditions don't usually cause pain below the knee. A herniated disc in the lower back can cause weakness in the legs and trouble lifting the front of your foot off the ground.
Herniated discs also occur in the neck (cervical spine). They can cause pain in one arm, beginning with the armpit and upper shoulder blade and travelling down the arm to one or two fingers. The pain can also be felt in the upper middle back and can be mistaken for other conditions. Arm muscles can weaken, making it hard to move the fingers.
Pressure on nerves at the bottom of the spinal cord can cause loss of bladder or bowel control, both of which are signs of very severe nerve pressure. Those symptoms, or loss of muscle function in the leg, are signs of a medical emergency, so get immediate medical attention if you experience these symptoms. The sooner you are seen, the more chance there can be some recovery of function.
Rarely, a ruptured disc in the neck can cause complete paralysis.