Sciatica

Sciatica is the name for pain caused by irritation or compression of the sciatic nerve, the longest nerve in the body. It is formed from nerve roots in the lower spine and runs through the buttock and down the back of each leg to the foot.

It is important to understand that sciatica is a symptom, not a diagnosis in its own right. The pain comes from a problem affecting one of the nerve roots where they leave the spine, or the nerve along its path. Identifying the underlying cause is part of managing it well.

Sciatica typically affects one leg at a time. The pain can range from a mild ache to a sharp, burning or shooting sensation, and it often follows a clear line from the lower back or buttock down the leg.

The main symptom is pain that travels from the lower back or buttock down the leg, and sometimes into the foot and toes. The pain is often worse when sitting, coughing or sneezing. Along with the pain there may be tingling like pins and needles, numbness, or weakness in the affected leg or foot.

Symptoms usually affect just one side. The exact pattern depends on which nerve root is involved. While sciatica can be very uncomfortable, in most cases it does not signal serious or permanent nerve damage and tends to settle over time.

The most common cause is a slipped (herniated) disc, where the soft cushion between the bones of the spine bulges out and presses on a nearby nerve root. Another frequent cause is spinal stenosis, a narrowing of the space in the spine that puts pressure on the nerves.

Less commonly, sciatica can result from a spinal injury, a slippage of one vertebra over another, or, rarely, a growth pressing on the nerve. Factors that can increase the risk include increasing age, being overweight, jobs involving heavy lifting or prolonged sitting, and previous back problems.

Sciatica is often diagnosed from the typical pattern of symptoms and a physical examination. A doctor may ask you to perform simple movements, such as lying down and lifting your leg, and will check the strength, reflexes and sensation in your legs to work out which nerve may be affected.

For most people, scans are not needed straight away, because sciatica usually improves on its own. Imaging such as an MRI scan may be arranged if symptoms are severe, do not settle over time, keep coming back, or if there are signs that suggest a more serious problem that needs further investigation.

Most cases of sciatica ease within a few weeks and can be managed at home. Staying gentle but active is usually better than bed rest, as keeping moving helps recovery; carrying on with everyday activities as far as the pain allows is encouraged. Heat or cold packs and changing position regularly can help with comfort.

Simple pain relief may be used, and a doctor or physiotherapist can suggest specific exercises and stretches to ease pressure on the nerve and strengthen the back. Physiotherapy is often helpful, particularly if symptoms are persistent.

If pain is severe or does not improve, further options may be considered. These can include stronger prescribed treatments, spinal injections to reduce inflammation around the nerve, and, in a small number of cases where a clear cause such as a slipped disc continues to compress the nerve, surgery to relieve the pressure.

Although most sciatica is not dangerous, certain symptoms point to a rare but serious condition called cauda equina syndrome, which needs emergency treatment in hospital. Seek immediate medical help if you have sciatica on both sides, severe or worsening weakness or numbness in both legs, numbness around or under your genitals or around your bottom, or new difficulty controlling when you pass urine or stool. These red-flag symptoms require urgent care to prevent lasting nerve damage.

For the great majority of people, the outlook is good. Sciatica often improves within a few weeks, and many people recover fully. Keeping active, maintaining a healthy weight, lifting carefully and using good posture can help prevent back problems and reduce the chance of sciatica returning.