Sciatica is often used as generalised term meaning pain from the sciatic nerve. Sciatica pain is caused by compression on the sciatic nerve, typically due to compression of the nerve the at spine, occasionally in the buttocks due to a tight piriformis muscle.
The Sciatic nerve is the longest and widest nerve in the body, which can cause pain into the buttocks, down the back of the leg. Just above the knee the nerve splits into two and continues as the Tibial Nerve and Common Peroneal Nerve, down to the foot.
Compression of the sciatic nerve at the spine can happen for a number of reasons. A “pinched nerve“ can be due to a herniated disc, inflammation (from irritation to the small joints in the back, or ligaments) or bone spurs which can develop, especially as we age.
The sciatic nerve passes close to, or through the Piriformis muscle. If the Piriformis is tight, it can lead to irritation of the sciatic nerve.
People often describe sciatica pain as a deep ache or shooting “electric“ type pain down the back of the leg or bottocks, and is often often accompanied by either sharp stabbing pains or a continual ache in the low back. Coughing and sneezing can sometimes replicate pain into the low back or into the leg. Commonly sciatica pain is only felt occasionally, and with low levels of discomfort. Typically over time the episodes will come on more and more frequently, lasting longer, with higher levels of pain. This is often due to the root cause of the problem not having been resolved and the body is unable to maintain compensatory movements to protect the area.
Treatment would typically involve techniques to “off load” the structures in the low back, whilst also treating the rest of the spine to reduce the chance of the problem returning, and to speed up recovery. Once pressure on the sciatic nerve starts to reduce, the pain should move closer to the spine (the source of the compression) until finally disappearing.
If you have symptoms down both legs at the same time, a central nervous system disorder such as spinal stenosis or growth should be considered and further clinical investigations would be indicated. Any changes to sensitisation to the saddle area (wiping your bottom for example) or sudden loss of control of bowel or bladder should be investigated as a matter of emergency.