Sciatica

Sciatica refers to pain felt along the path of the sciatic nerve, which branches from your lower back through your hips and buttocks and down each leg. Usually, sciatica affects only one side of your body.

Key points about sciatica 

  1. Sciatica is normally due to irritation of a spinal nerve. This is most commonly caused by a disc bulge or herniation, or age-related narrowing of the bones around the nerves.
  2. Common symptoms include pain, numbness, tingling, and weakness of your leg. The pain tends to run down the back of your leg in a thin line.
  3. Sciatica pain can also be felt in your back, but the leg pain is normally worse than the back pain.
  4. About half of people feel better by 4 weeks, but it can often last for several months or more.
  5. Rarely, injections and/or surgery may be recommended.

Call 111 and ask for an ambulance if you experience the following:

  • tingling or numbness in both legs and around your buttocks or genitals
  • weakness in both legs
  • loss of bladder or bowel control, or both (incontinence)
  • symptoms of sciatica in both your legs.

Although it's very rare, these symptoms can be a sign of a serious condition called cauda equina syndrome. This condition requires emergency surgery to prevent paralysis.

What is sciatica?

Sciatica is a term that generally refers to nerve pain in your leg caused by a problem in your lower back. The medical term for sciatica is ‘radicular leg pain’ because of the way the pain radiates from your back and hip into your legs through the spine.  

The sciatic nerve is a large nerve made up of several spinal nerves that branch from your lower back through your hips and buttocks and down each leg. Pain is usually felt along the path of the sciatic nerve. Sometimes there may also be numbness, tingling or muscle weakness in part of your leg. 

Sciatica is more common if you:

  • are a male
  • are aged between 30–50
  • drive or sit for more than 2 hours a day
  • carry heavy loads at work.

Other minor risk factors include smoking, stressful occupation and too little or too much physical activity. 

What are the causes of sciatica? 

The most common cause of sciatica is a herniated disc (also known as a ‘slipped disc’). This is when one of your spinal discs bulges into one or more spinal nerves, or when the outer fibrous layer breaks open and the inner toothpaste-like material oozes out. 

Spinal stenosis is another common cause. This is an age-related condition that slowly gets worse over time. It causes a narrowing of the nerve passages in your spine, which irritates or compresses one or more spinal nerves. 

Disc herniations and spinal stenosis do not always cause symptoms. Many people have these conditions and don’t know about it. They are only a concern if symptoms develop. 

Less common causes of sciatica are: 

  • spondylolisthesis – this is when a vertebra slips out of position and irritates or compresses a nerve root
  • a spinal or back injury or infection
  • a growth within your spine, such as a tumour
  • cauda equina syndrome, a rare but serious condition caused by compressed and damaged nerves in your spinal cord.  

What are the symptoms of sciatica?

The most common symptoms of sciatica are:

  • shooting, stabbing, electric shock pain that tends to start in your lower back and buttocks and runs down one leg past your knee and sometimes into your calf and foot
  • numbness, weakness or pins and needles in a part of your buttock, leg and foot
  • lower back pain – if you only have lower back pain, or if the pain in the leg is in a large area, then it is unlikely to be sciatica. Not all leg pain is sciatica.

Sciatica pain is usually felt within a 2cm wide line that runs down the back of your leg. Different areas of the leg are affected depending on which spinal nerve is irritated. 

The most common pattern is pain down your buttocks and the back of your leg, and down to your foot. The pain in your leg is normally worse than the pain in your back. There may be no back pain at all. 

The pain intensity can range from mild to severe, and it can start suddenly or gradually. Sneezing, coughing or sitting for a long period of time may make the pain worse. 

How is sciatica diagnosed? 

See your doctor if your pain is severe, ongoing or getting worse, if you have weakness or difficulty lifting your foot when walking, if your bowel or bladder is not working right, or if you have a fever or other symptoms that are worrying you. 

Your doctor will ask you questions about your symptoms and examine your back and nerves. 

Scans are not normally required for diagnosis. This is because most people will get better on their own, and so the scan does not change the treatment and is therefore not needed.

In the uncommon situation where a scan is needed, the best scan is an MRI scan. X-rays only show bone, not discs and nerves. MRI scans can be requested by non-GP specialists under ACC or under private health insurance. Some hospital specialists can also order them.  

How is sciatica treated? 

If your sciatica is caused by disc herniation, there is a 50% chance of being free of leg pain at 4 weeks – regardless of whether you have any treatment or not. However, the pain can last for several months or longer. Normally leg pain gets better faster than back pain. 

Some treatment options to discuss with your GP or doctor include: 

  • waiting it out, allowing your body to naturally heal
  • certain types of painkillers, such as anti-inflammatories and nerve pain medications
  • gentle exercises and stretches – you could consider gentle walking or swimming
  • physiotherapy – a physiotherapist can recommend suitable exercises for you, but this is normally not required
  • heat and cold – some people find heat or cold packs, or warm baths helpful
  • activity modification – reduce the amount of driving and prolonged sitting, and carrying heavy loads.

You may find a particular position that is pain relieving. Pain-relieving positions vary between people. One position may help some people but make the pain worse in others. 

In many people there is a psychological aspect to the pain that drives up the pain intensity and worsens function. Your brain and body exist as a whole. Some people find it helpful to address things like anxiety, fear and catastrophising. Learning coping and pacing skills may be helpful. 

If your symptoms are severe, your doctor may discuss the following options (which require referral to a relevant non-GP specialist):

  • Steroid injection – these are done using a scanning machine to safely guide the needle. The steroid is injected around the problem area in your spine to reduce swelling and inflammation.
  • Surgery – it is very uncommon to end up needing surgery, especially in the first few months. 

How can I prevent sciatica? 

There are no proven ways of preventing sciatica. The following may help:

  • Take regular breaks if you have a job that involves sitting for longer than 2 hours a day.
  • Do exercises to keep your back and core strong and flexible.
  • Avoid lifting heavy loads if you don’t have the strength for it.
  • Breathe with your stomach not your chest. 

Many people are surprised to hear that there is minimal or no evidence for the advice found in many lifting guidelines. Your spine is designed to bend, and there is no evidence that you should lift with a straight back. However, it is sensible to avoid lifting heavy loads if you don’t have the strength for it.

Take the following analogy. Clench your fist tightly and try to do something with it like bending it or lifting something. You will probably find that difficult and uncomfortable. Likewise, your back should be supple and loose when moving for most activities. 

For general health, which includes your back, the following lifestyle factors are important: maintaining a healthy body weight, stopping smoking if you smoke, reducing alcohol consumption, exercising regularly and eating a healthy diet. 

Learn more

Sciatica Better Health, Australia
Sciatica NHS, UK
Exercises for sciatica NHS, UK

References

  1. Sciatica NHS, UK, 2016 
  2. Kos BW, van Tulder MW, Peul WC. Diagnosis and treatment of sciatica BMJ 2007;334;1313-1317.
  3. Leg pain (sciatica) Iowa Clinic, US, 2013
  4. Management of non-specific back pain and lumbar radicular pain BPAC, NZ, 2009
  5. Sciatica Better Health, Australia, 2015
  6. Exercises for sciatica NHS, UK, 2015
  7. Taking care of your back Physiotherapy NZ, 2013
  8. Warm up, cool down and stretch ACC, NZ, 2002
  9. What type of mattress is best for people with low back pain Harvard Health Publications, US
  10. Tubach F, Beauté J, Leclerc A. Natural history and prognostic indicators of sciatica Journal of Clinical Epidemiology. 2004;57(2):174–179. 
  11. Bed rest for acute low back pain and sciatica Cochrane Database Syst Rev. 2000;(2):CD001254. 

Reviewed by

Jeremy Steinberg is a GP with special interests in musculoskeletal medicine, evidence-based medicine and use of ultrasound. He's been reviewing topics for Health Navigator since 2017 and in his spare time loves programming. You can see some of the tools he's developed on his website.
Credits: Health Navigator Editorial Team. Reviewed By: Dr Jeremy Steinberg, FRNZCGP Last reviewed: 07 Sep 2020