back pain: causes, red flags and when to see a physiotherapist

Back pain is one of the most common reasons people in the UK visit a physiotherapist, and it is rarely a sign of anything sinister. Around a third of the UK population — over 20 million people — live with a musculoskeletal condition, and low back pain is the leading cause of years lived with disability in this country. If you are worried about your back, you are far from alone, and there is a great deal you can do about it.

This guide, reviewed against the current NICE guideline NG59 (last reviewed 29 July 2026) and the NHS back pain page, walks you through the common causes of back pain, how to recognise the small number of symptoms that need urgent attention, and how physiotherapy can help you understand and manage yours.

 

What are the most common causes of back pain?

In most cases, the back hurts because muscles, ligaments, joints or discs have been irritated or overloaded — often by a combination of factors rather than one clear injury. Clinicians describe this as non-specific back pain because imaging rarely identifies a single culprit and it is not a serious sign. The most common contributors are set out below.

• Muscle or ligament strain — often triggered by lifting awkwardly, a sudden movement, or an accumulation of everyday load. This is the most common cause of a new episode.
• Facet joint irritation — the small joints at the back of the spine can become sensitive, particularly with prolonged standing or bending backwards.
• Sacroiliac (SI) joint pain — pain felt on one side of the low back, near the dimple above the buttock, often after prolonged sitting or postnatally.
• Disc-related pain — the intervertebral discs can become irritated, bulge or herniate. This may produce pain that is worse with sitting and, if a nerve is involved, symptoms into the leg.
• Nerve-related pain (sciatica / radiculopathy) — pain, tingling or weakness travelling down one leg, usually caused by irritation of a nerve root. Our guide to how physiotherapy can ease sciatica symptoms covers this in more detail.
• Spinal stenosis — a narrowing of the spinal canal, more common with age, that typically causes leg pain on walking or standing which eases when sitting or leaning forward.
• Spondylolisthesis — where one vertebra slips slightly forward on another, sometimes causing back pain with prolonged standing.
• Osteoarthritis of the spine — age-related changes in the spinal joints. Imaging findings do not always match symptoms, and many people with these changes have no pain at all.
• Inflammatory back pain (for example, ankylosing spondylitis) — a distinct pattern of morning stiffness that improves with movement, usually starting in younger adults.
• Osteoporotic compression fracture — sudden mid-back pain in an older adult, particularly following a minor trauma or in someone with osteoporosis or long-term steroid use, warrants urgent assessment.

Acute vs chronic back pain: what is the difference?

NICE distinguishes between the two based on how long the pain has lasted:

• Acute back pain lasts less than three months. Most episodes settle within a few weeks with sensible self-care and staying active.
• Chronic back pain lasts three months or longer. It is common, treatable, and rarely explained by a single structural problem — the biopsychosocial factors we discuss below become increasingly important.

Whether your pain is new or persistent, our clinical team can help you understand what is driving it. See our detailed guide to diagnosing and treating lower back pain for a walkthrough of what a first assessment involves.

Why does my back hurt in specific situations?

The pattern of your pain often gives useful clues about what is driving it. These are the situations patients ask us about most often.

Back pain after sitting

Pain that builds during long periods of sitting, particularly with a rounded lower back, is often disc-related. Discs are loaded more heavily in sitting than standing, and prolonged flexion can irritate them. Regular position changes, walking breaks, and targeted lower back exercises can help.

Back pain when standing or walking, easing on sitting

Pain and leg symptoms that come on with standing or walking and settle within a few minutes of sitting or leaning forward can suggest spinal stenosis, particularly in adults over 60. This pattern deserves an assessment so the right management plan can be put in place.

Back pain that is worse in the morning

Short-lived morning stiffness of 20–30 minutes is common and usually mechanical. Prolonged morning stiffness lasting more than 30 minutes that eases with movement, particularly in someone under 40, may suggest an inflammatory cause such as ankylosing spondylitis and warrants a medical review.

One-sided back pain

Pain on one side of the low back is often muscular or sacroiliac joint related. It responds well to a targeted exercise programme once the driver has been identified through a physical assessment.

Back pain with leg pain

Pain travelling below the knee — with or without tingling or weakness — usually reflects nerve involvement, most commonly sciatica. Symptoms in both legs, or any change in bladder or bowel function, are a red flag (see below) and need urgent assessment.

Back pain red flags: when to seek urgent help

Other symptoms that warrant a prompt GP appointment include:

• Unexplained weight loss, night pain, or a personal history of cancer — could indicate a serious underlying cause.
• Fever or feeling generally unwell alongside back pain — a possible sign of infection.
• Significant recent trauma, or a fall in someone with osteoporosis or on long-term steroids — a possible fracture.
• Prolonged morning stiffness over 30 minutes in a younger adult — possible inflammatory back pain.

These situations are rare, but recognising them matters. If none of these apply to you, it is very likely your back pain will improve with the right guidance.

Why pain isn't only about structures

Modern physiotherapy takes a biopsychosocial view of back pain, which is a fancy way of saying that we consider the whole person — not just an image of the spine. Sleep, stress, mood, past experiences of pain, how confident you feel about moving, and even beliefs about what a scan might show can all influence how much a back hurts and how quickly it settles.

This matters because it opens up more of the levers you can pull. Two people with an identical MRI can have very different experiences of pain. Understanding the drivers that are personal to you — and working on them together — is a central part of good physiotherapy care and something we build into every assessment.

How physiotherapy helps identify and manage the cause

NICE recommends a stepped, active approach for low back pain and sciatica. A physiotherapy assessment sits at the heart of this, and our chartered physiotherapists follow the current NICE-aligned pathway:

• Clinical assessment. A detailed history and physical examination to understand your pain, rule out red flags, and identify the likely driver. Routine imaging is not recommended in most cases and does not usually change treatment.
• Reassurance and education. Understanding what is (and is not) going on with your back is one of the most powerful things we can offer. Most back pain improves, and staying active is safe.
• Tailored exercise. A group or individual exercise programme, matched to what you enjoy and can sustain, is the intervention with the strongest evidence base.
• Manual therapy — as part of a package. NICE supports manipulation, mobilisation and soft-tissue techniques only when combined with exercise, not as a stand-alone treatment.
• Risk stratification. Tools such as the STarT Back questionnaire help us tailor the intensity of care to your risk of persistent pain.

NICE NG59 does not recommend a number of treatments for low back pain or sciatica, including traction, therapeutic ultrasound, TENS, PENS, interferential therapy, belts, corsets, acupuncture for low back pain, or paracetamol on its own. Where these are still marketed for back pain, they should be considered against the current evidence.

A short course of acupuncture or dry needling may be considered under the separate NICE guideline for chronic primary pain (NG193), which applies where pain is not fully explained by an underlying condition. Your physiotherapist can talk you through whether this is relevant for you.

When to see a physiotherapist for back pain

You do not need a GP referral to see a chartered physiotherapist in the UK. As a general guide, consider booking an assessment if:

• Your back pain has lasted more than a couple of weeks without improving.
• The pain is affecting your sleep, work, exercise or day-to-day life.
• You have had repeated episodes and want to understand why.
• You have leg symptoms, tingling or weakness alongside your back pain.
• You are less mobile — a friend, family member or carer can arrange a home visit across West London so care comes to you.

At CK Physio, our team of chartered physiotherapists specialising in musculoskeletal care assess and treat back pain at our clinic in Hanwell and across West London, including home visits when getting to a clinic is difficult. Learn more about our physiotherapy assessment or our physiotherapy service in Hanwell, West London.

Frequently asked questions

References and further reading

1. National Institute for Health and Care Excellence. Low back pain and sciatica in over 16s: assessment and management (NG59). Last reviewed 29 July 2026. nice.org.uk/guidance/ng59
2. National Institute for Health and Care Excellence. NG59 Recommendations. nice.org.uk/guidance/ng59/chapter/Recommendations
3. National Institute for Health and Care Excellence. Chronic pain (primary and secondary) in over 16s: assessment of all chronic pain and management of chronic primary pain (NG193) — Recommendations. nice.org.uk/guidance/ng193/chapter/recommendations
4. NHS. Back pain. Last reviewed 5 March 2026. nhs.uk/conditions/back-pain
5. Versus Arthritis. The State of Musculoskeletal Health. versusarthritis.org/about-arthritis/data-and-statistics/the-state-of-musculoskeletal-health
6. Health and Safety Executive. Working days lost in Great Britain. hse.gov.uk/statistics/dayslost.htm
7. Health and Safety Executive. Health and safety statistics — overview. hse.gov.uk/statistics/overview.htm
8. Hill JC, Kang S, Benedetto E, et al. Development and initial cohort validation of the Arthritis Research UK Musculoskeletal Health Questionnaire (MSK-HQ). BMJ Open 2016;6:e012331. ncbi.nlm.nih.gov/pmc/articles/PMC4985936
9. The Chartered Society of Physiotherapy. csp.org.uk