What is sciatica?
Sciatica refers to pain that travels down the back of the leg from the lower back or buttock to the foot due to irritation of the sciatic nerve. It is often accompanied by back pain, but normally the leg pain is worse than the back pain.
What causes it?
Our nerves leave the spine through small tunnels made by the bones of the spine. Some of these nerves in our lower back then merge to form the sciatic nerve. This happens on both sides of the spine and we therefore have a sciatic nerve running down each leg. If any of the nerves leaving the spine is irritated as it travels through the tunnel, either by swollen joints, muscles or ligaments, or due to a bulging disc, this can cause us pain anywhere along the length of the sciatic nerve.
A ‘slipped disc’ is a term commonly used for a weakness in the wall of the discs that sit between the bones of the spine causing the disc to bulge. The term is incorrect and discs do not slip, they bulge.
The sciatic nerves leave the spine in the lower back and travel into the buttock and down the leg to the lower leg and to the foot. When a sciatic nerve is irritated, as described previously, the irritation caused leads to severe, shooting pain travelling down all or part of the path of this nerve and can be accompanied with pins and needles and numbness. The sciatic nerves send messages to the brain about the irritation and it makes the brain think the problem is the nerve itself and not in the back which is actually the cause of the pain.
Why does the pain travel down the leg?
Keeping active is very important and you may find that you need to take regular pain relievers to achieve this. Use pain relievers to mask the pain as you need to keep active and you cannot do yourself any harm in doing so. By keeping mobile and doing gentle activity, you will stop your muscles becoming tight and weak – this may lead to long term problems. Remember if you have specific concerns it is important to discuss this with your physiotherapist.
Are there signs that I should be concerned about?
As highlighted earlier sciatica is only rarely the sign of a serious problem. We acknowledge it is very unpleasant, but the pain you experience does not mean ongoing damage is being done.
However if you experience any of the following you should seek urgent help:
- Being unable to pass urine when you feel the need to go.
- Loose control of your bowels.
- Go numb around your bottom.
- Unable to get an erection.
- Have pain in both legs and/or worsening weakness in the legs.