Imaging in adults with acute low back pain

Acute low back pain is common

Most people will experience acute (short-term, lasting less than two months) low back pain at some point in their lives. Your general practitioner (GP) can diagnose acute low back pain after listening to your story and examining you.

While the pain can be bad, fewer than 1% of people (one in 100 people) will have acute low back pain because of a more serious cause, such as a fracture or infection in your spine, pressure on your spinal cord or cancer.

Managing your acute low back pain

If your GP diagnoses you with acute low back pain, you are very likely to get better within four to six weeks.

During that time, you should try to maintain your usual routine and rest as you normally do. This includes going back to work, because you will recover more quickly if you keep doing your usual activities.

While the pain may seem worse when you move, movement will not cause any damage. Movement will:

• reduce your pain
• help you recover your normal range of movement
• help you get back to work and other normal activities more quickly.

Do not rest in bed, or on a couch, because this can make your pain worse and delay your recovery.

When you might need urgent medical attention

You should seek urgent medical attention if you develop any of the following:

• difficulty passing urine
• the sensation that you need to pass urine that is not there
• loss of bladder or bowel control
• numbness or tingling around your genitals, between your legs or buttocks
• impaired sexual function, loss of erections or sensation
• significant loss of power or a change in the sensation in both legs
• fever.

If your GP has told you that you have acute low back pain, you do not need to have an imaging test, unless they suspect a more serious condition. There are some good reasons for this.

Radiation from scans

In most cases of acute low back pain, a scan of the back will not show the cause of the pain, and won’t change treatment. The most common scans of the back (computed tomography [CT] scans and X-rays) will expose you to radiation.¹

Harmful consequences from scans

Scans will often show ‘changes’ that are the normal result of ageing, or are normal differences between people. This is especially the case with newer technologies such as CT and magnetic resonance imaging (MRI) scans.

When someone has a painful back, patients and doctors can both misinterpret the importance of these scan results. For example:

• the patient and doctor may conclude that these changes are the cause of the pain, and arrange other tests, procedures and treatments that won’t help with recovery, and could cause harms and side effects
• some patients may find the changes on the scans very frightening and worry that they will cause ‘more damage’ to their back if they remain active. This worry can slow recovery and stop them from getting better.

Expense

There is no Medicare rebate for an MRI scan of the lumbar spine that a GP requests, which means you will have to pay an out-of-pocket cost.

What if there is a serious cause of my acute low back pain?

Your GP will ask about your symptoms and medical background, then examine your back. If you do not have any of the known symptoms or background that suggest more urgent referral is needed, it is very unlikely that there is a serious cause for your low back pain, even if the pain is severe. Your back pain will likely go away in four to six weeks.

If, after four to six weeks:

• you still have pain, or
• your pain has become worse, or
• you have any other symptoms that you are worried about

book a follow-up appointment with your GP or physiotherapist, who will decide with you on the best course of action.

Can I have a scan for reassurance?

We don’t recommend scans for patients with acute low back pain as they:

• rarely help people get better
• expose people to radiation
• can lead to the wrong diagnosis
• can cause some people to worry to the point it slows their recovery.

• Get back to your usual activities as soon as possible. Start with gentle exercise, such as walking or light swimming. Gradually increase the amount of physical activity you do. This will help you to get better more quickly. The RACGP Handbook for non-drug interventions (HANDI) provides more information on staying active for acute low back pain.
• Get back to work as soon as possible. Talk to your boss/employer for any temporary adjustments to be made to your work or work area while you are recovering.
• Keep moving, and avoid bed rest, which can make the pain last longer.
• Try applying a heat pack to your back to see if it reduces your pain.
• If you need something to help with the pain, ask your GP or pharmacist about non-steroidal anti-inflammatory drugs (NSAIDS) like ibuprofen. Remember that:
  • medication will not take away all of the pain, but can sometimes make it more manageable
  • studies show that paracetamol on its own does not help with acute low back pain
  • strong pain medications, such as opioids, are not recommended because of their side effects and can slow your recovery.

• The RACGP, Handbook of non-drug interventions (HANDI), Heat therapy for low back pain 
• The RACGP, Handbook of non-drug interventions (HANDI), Staying active for acute low back pain 
• Department of Health, Government of Western Australia; Curtin University; University of Western Australia; Fremantle Hospital and Health Service, painHEALTH https://painhealth.csse.uwa.edu.au/about
• NPS MedicineWise, 10 things you need to know about low back pain
• NPS MedicineWise, Low back pain – do you need a scan?
• NSW Government and Agency for Clinical Innovation, Managing low back pain: Information for patients 
• University of Queensland, Arthritis Australia and the Cochrane Back and Neck Group
• The Australian Commission on Safety and Health Care, Low back pain clinical care standards 

If you still want a scan or X-ray of your back, discuss the pros and cons with your GP.

If your GP requests the scan or X-ray, make a follow-up appointment to review the findings, so you can understand the results and make an informed decision about how to manage your pain.