Sciatica

What is sciatica?

Sciatica describes the pain you feel when your sciatic nerve, the longest nerve in your body, becomes irritated somewhere along its route from your lower back, through your buttock, and down your leg. It usually settles on its own within a few weeks to a few months.

Back pain of some kind affects an estimated 60 to 80% of people in the UK at some point, and sciatica is one common cause of it.

What causes sciatica?

The most common cause is a slipped disc, also called a herniated disc, where the soft cushioning between the bones in your spine pushes out and presses on a nerve root. This becomes more likely as you get older.

Other spinal causes include spinal stenosis (narrowing of the space your nerves pass through) and spondylolisthesis (where one spinal bone slips forward out of position).

Sciatica can also follow a sprain or strain, such as an awkward lift, a sudden change in your activity levels, or conditions like osteoarthritis or rheumatoid arthritis. Poor sleep, stress or low mood won't cause sciatica on their own, but they can make a flare-up feel worse.

You might be more likely to develop sciatica if you:

• carry extra body weight, which adds strain to your spine
• have a job involving heavy lifting, twisting, or long spells of sitting or driving
• have weak core muscles, or generally low activity levels
• have diabetes, which can affect the health of your nerves
• smoke, since this can reduce blood flow to your spine.

Are there different types of sciatica?

Sciatica is usually described by its cause or how long it lasts. One useful distinction is between true sciatica, where an injury or condition directly affects the sciatic nerve, and sciatica-like pain, which feels the same but comes from a nearby nerve or from the smaller nerves that join together to form it.

It also helps to think of sciatica as acute or chronic. Acute sciatica, often triggered by a specific strain or disc problem, tends to ease within a couple of weeks and keeps improving over the following weeks or months. Chronic sciatica lingers for months or even years, particularly when the underlying cause isn't dealt with.

How is sciatica diagnosed?

Sciatica is usually diagnosed from your symptoms and a physical examination, rather than from scans. Your doctor may watch how you walk and carry out a straight leg raise test, gently lifting one leg at a time while you lie down, to see where and when your pain starts.

X-rays and scans aren't usually needed. They can't show how much pain you're in, and they often pick up normal age-related changes that don't explain your symptoms or change your treatment. A scan is more likely if your symptoms are severe, are getting worse, aren't settling as expected, or if your doctor wants to rule out a rarer, more serious cause.

How is sciatica treated?

Non-surgical treatment

Most people recover with simple self-care and time. Helpful steps include:

• staying as active as you can and continuing your normal activities where possible, rather than resting in bed for long periods
• gentle stretching and exercises, such as knee-to-chest stretches or cat-cow style movements
• ice packs for the first couple of days, then heat afterwards, held on for around 15 to 20 minutes at a time
• over-the-counter pain relief such as ibuprofen – paracetamol on its own is less likely to help with this type of nerve pain.

If self-care isn't enough after a few weeks, your GP might suggest physiotherapy (which combines guided exercises with hands-on techniques such as massage), or prescribe stronger pain relief or muscle relaxants.

Some people also find osteopathy helpful, which uses hands-on techniques like stretching and gentle manipulation to ease pressure on the nerve.

Surgical and procedural treatment

Surgery is a last resort, used when symptoms are severe or aren't responding to other treatments:

• A spinal injection: Such as an epidural, to calm inflammation around the nerve and ease pain
• Radiofrequency denervation: A procedure that seals off the nerves sending pain signals
• Decompression surgery: Such as a discectomy or laminectomy, to remove whatever is pressing on the nerve.

When should I see a doctor?

See your GP if your leg pain hasn't improved after trying self-care for 3 to 4 weeks, is getting worse, or is stopping you doing your normal activities.

Go to A&E or call 999 straight away if you have any of the following:

• sudden numbness or weakness in a leg after a violent injury, such as a road traffic accident
• numbness or weakness in both legs, especially if it's severe or getting worse
• numbness around your genitals, inner thighs or your back passage
• new difficulty starting to pee, or being unable to control when you pee
• not noticing when you need to poo, or losing control of your bowels.

The last four of these can be signs of a rare but serious condition called cauda equina syndrome, where the nerves at the base of your spine become severely compressed. Don't drive yourself to A&E with these symptoms – ask someone else to drive you, or call 999 for an ambulance.