Sciatica is pain affecting the back, hip, and outer side of the leg, caused by compression of a spinal nerve root in the lower back, often owing to degeneration of an intervertebral disc.
What is sciatica and what is the cause?
Sciatica is not a diagnosis, but it is a symptom of an issue and a reasonably rare one at that. The symptoms of sciatica is caused by compression or inflammation of the sciatic nerve. This causes pain down the back of either the left or right leg that can extend to the foot. If compression of the nerve is severe, numbness and decreased muscle strength can also be found over the affected leg, although this is somewhat rare. By far the most common cause of sciatic nerve symptoms is a herniated or bulging disc, which then causes inflammation of the sciatic nerve. A bulging disc is caused by pressure on the front section of a spinal disc, this forces the fluid in the disc backwards, then the wall of the disc can break down and cause leakage of the fluid within the disc. We generally use the analogy of a doughnut, if you squeeze one side of a doughnut, you push the jam to the other side, do this repeatedly and the jam breaks down the dough and leaks out. Think of a spinal disc as the doughnut…If this helps? Although bulging discs can cause sciatic nerve symptoms, they are also very common in people who don’t have pain (see “Is Your MRI Right?”).
What is not sciatica?
- Sharp pains. But just because pain is sharp does not mean it is being caused by a nerve.
- Pain down the front of the leg, groin or outside of the leg. This is far more likely to be hip pain.
- Pain in the lumbar spine itself. There is a saying in physiotherapy, its: “all nerve pain is referred pain, but not all referred pain is nerve pain”. In essence, nerve pain is always felt in another part of the body, but not all pain that is felt elsewhere is nerve pain. Sciatic symptoms are never felt in your back.
- Leg pain alone is unlikely to be because of your spine. I would say it is possible to have sciatic symptoms without lower back pain but this is extremely rare, it is more likely to have concurrent back pain.
- Whole leg numbness or weakness. The sciatic nerve works to supply specific muscles and areas of skin, whole weakness of the leg and numbness is unlikely to be caused by compression of the sciatic nerve.
In my experience, most cases of people presenting with what they think is sciatica, is more likely to be concurrent lower back and hip pain. The causes of the hip pain are varied but the most common cause would be hip osteoarthritis, a very treatable condition. If you do have lower back and leg pain or think you may have sciatica, get an assessment at either your GP or our physiotherapy clinic to get a diagnosis. Remember we are still offering a free 20 minute consultation! Call for advice or to book in now on 0151 345 6823 or email [email protected]