Low back pain causes pain and disability, with a significant social and economic impact on sufferers and society at large, as Steve Titmarsh explains… 
 
 
Low back pain affects about 60–70 per cent of people in industrialised countries at least once during their lifetime,1 but only around 1 in 5 people with the condition go to their GP each year.  
 
Approximately 5–7 per cent of people over the age of 45 years are chronically disabled by low back pain.2 It affects people’s lives by limiting their activities and causing them to take time off work, which has economic consequences for both individuals and society as a whole.1  
 
Lower back pain generally describes pain affecting the part of the back between the bottom of the ribs and the top of the legs.3 It can be acute, lasting from a few days to a few weeks, or it can be chronic, lasting for 12 weeks or more.4  
 
A number of risk factors influence an individual’s susceptibility to low back pain, including:2,4  

• Age: back pain typically first affects people between the ages of 30-50 years and is more common as they age.
• Fitness: People who are unfit are more prone to back pain. Sudden bursts of physical exercise after days of being sedentary can also result in injury and pain.
• Obesity: Being overweight or gaining weight quickly can be a risk factor for developing back pain.
• Genetics: Ankylosing spondylitis, for example, has a genetic link and can be a cause of back pain.
• Depression: A person’s mood can have a bearing on their susceptibility to low back pain.  

Types and causes 
Often the cause of low back pain is not clear, in which case it is it is usually referred to as non-specific. On many cases the most likely cause is that someone has sprained a ligament or muscle through overstretching, for example by lifting a heavy object (perhaps because they have used incorrect technique or that it is simply too heavy for them to lift safely), or through injury.3,4 
 
Nerve root pain, also known as sciatica, is due to pressure on a nerve or inflammation of a nerve. Most cases are caused by a prolapsed disc (referred to colloquially as a slipped disc). A clue that a person has sciatica rather than non-specific back pain is that they describe the pain as affecting only one leg, usually radiating from below the knee to the foot or toes. It is more severe than the back pain, and they may also experience numbness, tingling and muscle weakness.3  
 
Arthritis can sometimes cause back pain, as can conditions such as osteoporosis, other bone disorders, tumours and infection.3 
 
Cauda equina is a rare but serious problem that can cause back pain but will also affect bladder and bowel function. It happens when pressure is exerted on the nerves at the very base of the spine and it needs urgent medical attention to prevent the nerves to the bladder and bowel being permanently damaged.3  
 
Non-specific back pain that is not associated with serious causes will usually resolve within four weeks with self-care. A primary care study in Australia, for example, found that 40 per cent of people with acute low back pain were pain free after six weeks and almost three-quarters (73 per cent) had no pain after a year.5  
 
Management 
In general, guidelines from around the world on the treatment of acute non-specific low back pain in adults recommend reassuring patients that the outcome is usually good, advising them to avoid bedrest and return to normal activities as much as possible (while avoiding anything that causes a lot of pain). 
 
Non-steroidal anti-inflammatory drugs (NSAIDs), or weak opioids (but only if NSAIDs are contraindicated or have not been tolerated or effective) can be taken for short periods at the lowest possible dosage if needed. NSAIDs, exercise therapy and psychosocial interventions are recommended for chronic low back pain.6,7  
 
Information for patients about low back pain, as well as encouragement to continue with normal activities or to consider a group exercise programme (to deal with a specific flare up of pain) need to take account of individual needs, preferences and capabilities.6  
 
A Cochrane review of 32 trials found that NSAIDs such as diclofenac, ibuprofen and naproxen were slightly better than placebo at relieving acute low back pain but not to an extent that would be considered clinically relevant. On average the intensity of pain fell by 7.3 points on a 100-point scale in people who took an NSAID. Disability scores improved slightly when people took an NSAID compared with placebo as well, but again probably not enough to produce a significant benefit.1  
 
Another recent Cochrane review also concluded that paracetamol (4g per day) is no better than placebo for relieving acute low back pain.8 The National Institute for Health and Care Excellence (NICE) no longer recommends offering paracetamol alone for managing low back pain.6 
 
The outlook for people with back pain that has no serious complications is generally good. There are a number of strategies they can use to manage their pain. They can be advised about lifestyle changes, including keeping fi and maintaining a healthy weight,3 and they can try to reduce the chance of the problem recurring. 
 
When to refer… 
Patients in the following categories should be advised to see their GP without delay:2,9,10  

• pain does not improve after a few weeks
• severe pain that becomes worse with time
• pain that stops a person getting on with their day-to-day life or disturbs sleep
• pain in the chest or upper back
• weakness, numbness or tingling in one or both legs
• signs of infection, such as fever
• recent problems with incontinence or difficulty urinating 
   

References

1. van der Gaag WH, Roelofs PDDM, Enthoven WTM, et al. Non‐steroidal anti‐inflammatory drugs for acute low back pain. Cochrane Database of Systematic Reviews 2020;4:CD013581.

2. Clinical Knowledge Summaries. Low back pain (https://cks.nice.org.uk/topics/back-pain-low-without-radiculopathy/background-information/prevalence; accessed 2 July 2021).

3. https://patient.info/bones-joints-muscles/back-and-spine-pain/lower-back-pain; accessed 1 July 2021.

4. US Department of Health and Human Services. National Institute of Neurological Disorders and Stroke. National Institutes of Health (NIH). Low back pain. Bethesda, Maryland, USA: NIH, 2020.

5. Clinical Knowledge Summaries. Back pain – low (without radiculopathy): What is the prognosis? (https://cks.nice.org.uk/topics/back-pain-low-without-radiculopathy/background-information/prognosis; accessed 2 July 2021).

6. National Institute for Health and Care Excellence (NICE). Low back pain and sciatica in over 16s: assessment and management (www.nice.org/guidance/ng59; accessed 5 July 2021).

7. Oliveira CB, Maher CG, Pinto RZ, et al. Clinical practice guidelines for the management of non-specific low back pain in primary care: an updated overview. Eur Spine J. 2018;27(11):2791–803.

8. Saragiotto BT, Machado GC, Ferreira ML, Pinheiro MB, Abdel Shaheed C, Maher CG. Paracetamol for low back pain. Cochrane Database Syst Rev. 2016;2016(6):CD012230.

9. www.nhs.uk/conditions/back-pain; accessed 5 July 2021.

10. www.mayoclinic.org/symptoms/back-pain/basics/when-to-see-doctor/sym-20050878; accessed 5 July 2021.