The sciatic nerve, which runs from the back of the pelvis, through the buttocks and down to the feet, is the longest nerve in the body. If something puts pressure on this nerve, it’s known as sciatica.

Causes

The most usual cause of sciatica is a slipped disc. However, there are other causes, including:

• Pregnancy, when the growing baby puts pressure on the sciatic nerve
• Spinal stenosis (narrowing of the nerve passages in the spine)
• Injury
• Infection (rarely)
• A spinal tumour (very rarely)

Symptoms

These include pain that spreads from the lower back, down the buttocks and usually all the way down one or both legs. Pain can be mild or very painful and can become worse, especially when you stand or sit down for a long time, or lean backwards. You may also have muscle weakness, tingling and numbness. In very rare cases, sciatica can be a sign of a more serious condition known as cauda equine syndrome, so you should see a doctor straight away (or go to Accident & Emergency at your nearest hospital as soon as possible) if you also experience loss of control of your bladder or bowel, weakness in your foot or leg or numbness in your buttocks, lower back and leg.

Diagnosis

Sciatica may go away without the need for any treatment. However, if you are still experiencing painful symptoms after a few weeks, you should ask your doctor for advice. A diagnosis is usually made during a medical examination using the ‘passive straight leg raise test’. You will be asked to raise your leg, while lying flat on your back; the doctor will then raise the foot up and if this makes the pain worse, it’s likely to be sciatica. You may also be given a blood test to check for infection; an X-ray; and a CT or MRI scan to check if there are any other problems.

Treatment

Treatment includes anti-inflammatory medicine, if advised by your doctor, and in some cases you may be prescribed stronger painkillers. Staying active and taking gentle exercise can also help, as well as applying ice (crushed and wrapped in a towel) several times a day for around 15 minutes to reduce pain and swelling. If the sciatica is due to a slipped disc, you may be referred to a specialist for procedures including spinal injections; if these are unsuccessful you may be offered discectomy, fusion surgery or laminectomy.

Important: This information is only a guideline to help you understand your treatment and what to expect. Everyone is different and your rehabilitation may be quicker or slower than other people’s. Please contact us for advice if you’re worried about any aspect of your health or recovery.