Inflammatory vs Mechanical Back Pain: Why the Difference Matters

Black and white X-ray image of the lower spine and pelvis with red highlighting over the sacroiliac joints to indicate inflammation.

Back pain is one of the most common reasons people see their GP — but not all back pain is the same. One of the most important distinctions we make in rheumatology is whether pain is mechanical or inflammatory. Identifying the correct type early can completely change the treatment plan, the long-term outlook, and how quickly patients feel better.

At my clinic, I regularly see patients who have lived with persistent back pain for months or years, often believing it is “just a strain,” “ageing,” or “a disc issue.” In many cases, their symptoms actually point towards an underlying inflammatory condition that needs a totally different approach.

This guide explains the key differences — and when to consider a rheumatology assessment.

What Is Mechanical Back Pain?

Mechanical back pain is the type most people are familiar with. It usually comes from the muscles, joints, ligaments, or discs in the spine.

Common causes

  • Muscle strain or spasm

  • Poor posture or prolonged sitting

  • Osteoarthritis (“wear and tear”)

  • Disc degeneration or bulging discs

  • Facet joint pain

  • Sciatica due to nerve compression

Typical features

  • Worse with activity, lifting, bending, or twisting

  • Better with rest

  • Pain may be sharp, localised, or radiate down the leg

  • Often triggered by a specific movement or injury

  • Morning stiffness is brief, usually minutes rather than hours

Treatment usually includes:

  • Physiotherapy

  • Exercise rehabilitation

  • Core strengthening

  • Posture changes

  • Pain relief when required

Mechanical pain is extremely common — and usually improves gradually with the right support.

What Is Inflammatory Back Pain?

Inflammatory back pain comes from inflammation in the spine or sacroiliac joints (SI joints). This can be due to an underlying autoimmune condition, often in the spondyloarthritis (SpA) family.

The most important condition to identify early is:

Axial Spondyloarthritis (axSpA)

This includes the condition previously known as ankylosing spondylitis.

Inflammatory back pain often starts gradually, frequently in people under 45, and does not improve with rest.

Typical features

Patients often describe:

  • Pain and stiffness first thing in the morning, lasting >45 minutes

  • Improvement with movement and exercise, not rest

  • Night pain — waking in the second half of the night

  • Alternating buttock pain

  • Symptoms lasting more than 3 months

  • Onset typically under the age of 45

Other clues suggesting an inflammatory cause

  • A history of uveitis (eye inflammation)

  • Psoriasis

  • Crohn’s or ulcerative colitis

  • A family history of spondyloarthritis

  • Enthesitis (pain where tendons attach to bone, e.g. Achilles)

  • Good response to NSAIDs

Why early diagnosis matters

Left untreated, inflammation can cause:

  • Ongoing pain and stiffness

  • Loss of mobility

  • Structural changes to the spine

  • Fatigue and reduced quality of life

Modern treatments — including advanced biologic therapies — can transform symptoms and protect long-term spinal health.

How Inflammatory and Mechanical Back Pain Differ

Age of onset

  • Mechanical: Can occur at any age

  • Inflammatory: Often begins before age 45

Morning stiffness

  • Mechanical: Lasts only a few minutes

  • Inflammatory: Lasts more than 45 minutes

What improves symptoms

  • Mechanical: Rest usually helps

  • Inflammatory: Exercise and movement help

What worsens symptoms

  • Mechanical: Activity, bending or lifting

  • Inflammatory: Rest, inactivity or long periods sitting still

Night pain

  • Mechanical: Uncommon

  • Inflammatory: Common, especially in the second half of the night

Response to anti-inflammatory medication (NSAIDs)

  • Mechanical: May help slightly or not at all

  • Inflammatory: Often a dramatic improvement

Underlying cause

  • Mechanical: Muscles, joints, discs, posture or wear-and-tear

  • Inflammatory: Autoimmune inflammation of the spine or sacroiliac joints

How I Assess Back Pain in Clinic

During your consultation, I take a thorough history and examination, looking for subtle signs of inflammation that are easily missed. Depending on your symptoms, I may recommend:

  • MRI of the spine or sacroiliac joints (far more sensitive than X-ray)

  • Blood tests including inflammatory markers and HLA-B27

  • A tailored physiotherapy plan

  • Anti-inflammatory medications where appropriate

  • Early access to specialist biologic treatments if inflammation is confirmed

My approach is holistic: I look at your symptoms, lifestyle, sleep, mobility, and overall health — not just the spine in isolation.

When to See a Rheumatologist

You should consider a specialist review if you have:

  • Persistent back pain for >3 months

  • Morning stiffness lasting over 45 minutes

  • Pain that improves with exercise but returns at rest

  • Night pain that wakes you

  • Alternating buttock pain

  • A history of psoriasis, IBD, uveitis, or a family history of arthritis

  • Tried physiotherapy but symptoms remain unexplained

Early diagnosis can prevent years of discomfort and help you return to the activities you enjoy.

If This Sounds Like You, I Can Help

I offer rapid access appointments at the Physicians’ Clinic, the Devonshire Diagnostic Centre, and Chiswick Medical Centre for patients with back pain who want clarity and a personalised plan.

If you think your back pain may be inflammatory, early assessment can make a significant difference.

👉 Book an appointment
👉 Or contact my PA: DrSinghPA@ThePhysiciansClinic.co.uk / 0203 9855778

Dr Animesh Singh, Consultant Rheumatologist. GMC: 6130215


Please note, these posts are for general information only and do not constitute medical advice. Dr Singh would encourage you to speak to your healthcare professional to be assessed and managed for your specific symptoms.

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