A slipped disc means that one of the discs of cartilage in the spine is damaged and pressing on the nerves.
It's also known as a prolapsed or herniated disc.
The spine, or backbone, is made up of 24 individual bones called vertebrae, which are stacked on top of each other.
In between each vertebra there are circular pads of connective tissue (cartilage) called discs. These discs have an inner gel-like substance and a tough outer case. They help maintain your back's flexibility and wide range of movement.
The spinal cord is a sensitive bundle of nerve fibres that passes through the middle of the spine. These nerve fibres connect all parts of the body to the brain.
Symptoms of a slipped disc
A slipped disc can cause back pain and neck pain. Other typical symptoms are numbness, a tingling sensation and weakness in other areas of the body.
The sciatic nerve is often affected in cases of slipped disc. It's the longest nerve in the body and runs from the back of the pelvis, through the buttocks, and down both legs to the feet.
If pressure is placed on the sciatic nerve (sciatica), it can cause mild to severe pain in the leg, hip or buttocks.
Not all slipped discs cause symptoms such as pain, weakness or tingling. Many people will go their whole life not knowing they have slipped a disc.
What causes a slipped disc?
A slipped disc occurs when the circle of connective tissue surrounding the disc breaks down, allowing the soft, inner gel-like part of the disc to bulge out.
The damaged disc can put pressure on the whole spinal cord or on a single nerve root, where a nerve leaves the spinal cord.
This means a slipped disc can cause pain in the area of the protruding disc and also in the area of the body controlled by the nerve that the disc is pressing on.
It's not always clear what causes a disc to break down, but age is a common factor in many cases.
As you get older, your spinal discs start to lose their water content, making them less flexible and more likely to split (rupture).
Smoking can also be associated with a slipped disc because it causes the discs to lose their natural flexibility.
Other factors that can put increased pressure and strain on your spine include:
heavy or awkward lifting
sitting for long periods, particularly when driving
being overweight or obese
weight-bearing sports, such as weightlifting
severely injuring your back, such as during a fall or car accident
These situations can weaken the disc tissue and sometimes lead to a slipped disc.
What is the risk of having a slipped disc?
Slipped discs are most common in people aged between 30 and 50. They affect twice as many men as women.
Slipped discs often occur in the lower back.
Diagnosis of a disc herniation
Your primary care physician, pain physician or spine surgeon will usually be able to diagnose a slipped disc from your symptoms and medical history.
They may also carry out a physical examination to test your:
sensation in your limbs
Treating a slipped disc
It can take about one to three months to recover from a slipped disc. Treatment usually involves a combination of physiotherapy, such as massage and exercise, medication and injection to relieve the pain.
Epidural injections often provide much needed relief for cases which are either too painful or limit you in doing other methods to recover.
Surgery to release the compressed nerve and remove part of the disc may be considered in severe cases, or if the pain doesn't settle down over time.
In many cases, a slipped disc will eventually shrink back away from the nerve and the pain will ease as the disc stops pressing on the affected nerve.
Sometimes the slipped disc will stay pressing on the nerve, but the pain goes away because the brain learns to "turn down the volume" on the pain messages coming from the nerve.
It's very important to keep active if you have a slipped disc. Moving may be difficult to start with, but you should start to move around after resting for a couple of days.
This will help keep your back mobile and stop the joints becoming stiff and the muscles that support the spine becoming weak. Keeping moving will speed up your recovery.
You should only exercise gently to ensure you don't put too much strain on your back. At first, avoid high-impact exercises, such as running, jumping or twisting, as they may cause the pain to flare up.
Preventing a slipped disc
Taking a few sensible precautions, such as leading a healthy lifestyle, can help prevent back pain and lower your risk of getting a slipped disc.
For example, you should:
do regular exercise
use a safe technique when lifting heavy objects
always maintain a good posture when sitting and standing
give up smoking if you smoke
Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2)