Inflammatory Back Pain – When to Seek Specialist Advice
Back pain is extremely common and, for most people, relates to mechanical or muscular problems that improve with time. However, a smaller but important group of patients experience inflammatory back pain, which has a different cause, behaves differently, and requires a different approach to investigation and treatment.
Recognising inflammatory back pain early is important, as timely diagnosis and treatment can significantly improve symptoms and help prevent long-term problems.
What Is Inflammatory Back Pain?
Inflammatory back pain is caused by immune-mediated inflammation affecting the spine and pelvis, particularly the sacroiliac joints and spinal joints.
Unlike mechanical back pain, which is related to strain, posture or degeneration, inflammatory back pain reflects an overactive immune response driving inflammation within joints and surrounding structures.
It is most commonly seen in conditions within the spondyloarthritis spectrum, including:
axial spondyloarthritis (axSpA)
ankylosing spondylitis
psoriatic arthritis with spinal involvement
Axial Spondyloarthritis and Ankylosing Spondylitis
Axial spondyloarthritis is the term used for inflammatory arthritis that primarily affects the spine and sacroiliac joints.
It includes:
non-radiographic axial spondyloarthritis, where inflammation is present but X-rays are normal
ankylosing spondylitis, where longer-standing inflammation has led to visible structural changes on X-ray
Many patients have symptoms for years before X-ray changes develop. This is why MRI has become central to diagnosis, particularly in younger patients with persistent inflammatory symptoms.
How Is Inflammatory Back Pain Different From Mechanical Back Pain?
The pattern of symptoms provides important clues.
Inflammatory back pain typically:
begins gradually, often before the age of 40
causes morning stiffness lasting more than 30–45 minutes
improves with movement and exercise
worsens with rest or inactivity
may cause pain during the second half of the night, sometimes waking people from sleep
Mechanical back pain, by contrast, usually:
comes on suddenly or after a specific strain
improves with rest
worsens with activity or certain movements
causes little or no morning stiffness
These differences are not always clear-cut, which is why careful clinical assessment is essential.
(More information about Inflammatory vs. Mechanical Back Pain).
Why Inflammatory Back Pain Is Often Missed
Inflammatory back pain is well recognised to be associated with delays in diagnosis, often measured in years.
This happens because:
back pain is extremely common and usually mechanical
early inflammatory symptoms may be intermittent
physical examination findings can be subtle
blood tests are often normal
early X-rays may appear reassuring
Many patients are told that investigations are normal, despite ongoing symptoms.
The Role of HLA-B27
HLA-B27 is a genetic marker associated with axial spondyloarthritis and ankylosing spondylitis.
Key points:
HLA-B27 is not diagnostic on its own
many people who carry HLA-B27 never develop arthritis
some patients with inflammatory back pain are HLA-B27 negative
A positive HLA-B27 result can support a diagnosis when symptoms and imaging are suggestive, but a negative result does not rule inflammatory spinal disease out.
Links With Other Inflammatory Conditions
Inflammatory back pain often occurs alongside other immune-mediated inflammatory diseases.
Some patients also have:
psoriasis or psoriatic arthritis
inflammatory bowel disease
uveitis (eye inflammation)
tendon or heel pain (enthesitis)
These overlaps reflect shared immune pathways and help explain why treatments can be effective across joints, skin, eyes and the gut (explored further in Psoriatic Arthritis Explained).
How Is Inflammatory Back Pain Investigated?
Assessment usually includes:
Clinical Assessment
detailed symptom history
pattern and timing of pain and stiffness
associated joint, skin, eye or bowel symptoms
Physical Examination
spinal movement
sacroiliac joint tenderness
assessment of peripheral joints and tendons
Imaging
MRI of the sacroiliac joints is often the most informative test
MRI can detect active inflammation before X-ray changes develop
ultrasound may identify associated tendon or joint inflammation
Imaging is particularly important when blood tests are normal but symptoms suggest inflammatory disease.
Why Early Diagnosis Matters
Early recognition of inflammatory back pain is important because it allows:
earlier symptom control, improving pain, stiffness and sleep
prevention of long-term structural damage
access to effective modern treatments, including biologic therapies where appropriate
Delayed diagnosis can result in years of pain, uncertainty and functional limitation. Early assessment helps provide clarity and a clear management plan.
Treatment Options
Treatment depends on disease severity and pattern but may include:
anti-inflammatory medication
physiotherapy and targeted exercise
disease-modifying or biologic therapies in more active disease
Biologic treatments, including anti-TNF therapies, are highly effective for many patients and are discussed in more detail in Anti-TNF Treatments in Rheumatology – What they are and how they help.
When to Seek Rheumatology Advice
You should consider specialist assessment if back pain:
starts before age 40 and lasts longer than 3 months
is associated with prolonged morning stiffness
improves with movement but not rest
disturbs sleep
occurs alongside psoriasis, inflammatory bowel disease or uveitis
persists despite normal blood tests
A structured rheumatology assessment helps determine whether symptoms are inflammatory, mechanical or a combination of both.
In Summary
Inflammatory back pain behaves differently from mechanical back pain
It is commonly part of axial spondyloarthritis
Blood tests may be normal and HLA-B27 is supportive but not definitive
MRI plays a key role in diagnosis
Early recognition and treatment improve outcomes
Persistent back pain with inflammatory features deserves careful evaluation, even when initial tests appear reassuring.
Trusted Patient Information Resources
Arthritis UK
Patient-friendly information on axial spondyloarthritis and inflammatory back pain.
NHS
Overview of ankylosing spondylitis and inflammatory back pain.
National Axial Spondyloarthritis Society
Specialist patient resources focused on axial spondyloarthritis.
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.