Also called: Ankylosing spondylitis; axial spondyloarthritis
Exercise is the main treatment
Strength
Stretch
Breathing
Back pain in a young adult that is worse with rest, wakes them in the second half of the night and improves with movement. That pattern is the opposite of mechanical back pain - and the average delay to diagnosis is still measured in years.
How common: 0.1-0.5% of adults; typically starts under 45; often diagnosed 7+ years late
What it is
Axial spondyloarthritis, including ankylosing spondylitis, is inflammation at the sacroiliac joints and the entheses of the spine. Left unmanaged it can lead to new bone formation and progressive spinal fusion.
The diagnostic pattern is distinctive and reversed from ordinary back pain: it starts before forty, comes on gradually, is worse with rest and better with exercise, produces morning stiffness lasting over half an hour, and wakes people in the second half of the night. Despite that, the average delay from symptom onset to diagnosis remains several years.
What it feels like
- Low back and buttock pain starting before the age of forty
- Worse with rest and after inactivity, better with movement
- Waking in the second half of the night with pain, and getting up to move around
- Morning stiffness lasting more than half an hour
- Sometimes alternating buttock pain, heel pain, eye inflammation or bowel symptoms
What causes it
Most people have more than one of these at once, and they feed each other. Read the
list looking for the two or three that sound like your week rather than for the one
true answer — the ones that describe you are the ones worth acting on.
- Inflammation at the sacroiliac joints and spinal entheses
- The immune system targets where ligaments and tendons attach to the spine and pelvis. That inflammation produces the pain and, over time, drives new bone formation.
- New bone formation and fusion
- The healing response to repeated inflammation lays down new bone, which can eventually bridge between vertebrae. This is what produces the progressive stiffness and, in advanced cases, fusion.
- Genetics
- The HLA-B27 gene is present in the large majority of people with ankylosing spondylitis, though most people carrying it never develop the disease. Family history is a strong risk factor.
- Male sex and age of onset
- More commonly diagnosed in men, and onset is typically in the late teens to early thirties. It is under-diagnosed in women, whose presentation is often less classic.
- Associated conditions
- Inflammatory bowel disease, psoriasis and recurrent eye inflammation all cluster with it and are important diagnostic clues.
- Smoking
- Associated with worse disease progression and more rapid structural damage. Stopping is one of the most valuable things a patient can do.
- Being treated as mechanical back pain
- The most consequential factor in outcomes. Years of physiotherapy for mechanical back pain in someone with an inflammatory pattern delays the treatment that would prevent damage.
- Reduced spinal mobility from inactivity
- The disease stiffens the spine, and inactivity stiffens it further and faster. A great deal of the loss of movement is preventable.
- Reduced chest expansion
- Inflammation at the rib-spine joints restricts breathing over time. Maintaining chest expansion is a specific and often overlooked treatment target.
Who tends to get it
- Adults under forty with back pain that fits the inflammatory pattern
- Anyone carrying HLA-B27 or with a family history
- People with inflammatory bowel disease, psoriasis or recurrent eye inflammation
- Men, though it is substantially under-diagnosed in women
- Anyone whose back pain improves with exercise and worsens with rest
What makes it worse, and what settles it
Makes it worse
- Rest and inactivity, which is the reverse of mechanical back pain
- Prolonged sitting and sustained static postures
- Smoking, which accelerates structural damage
- Delay in diagnosis, which allows preventable fusion
- Being managed as mechanical back pain for years
Settles it
- Getting the right diagnosis, which is the single most valuable step and is frequently delayed
- Daily exercise, which is the cornerstone of management and genuinely relieves the symptoms
- Spinal mobility and extension work, done every day, to preserve the range
- Breathing and chest expansion exercises, which are specific to this condition
- Strength training, which supports the spine and counters the associated bone loss
What actually helps
The short version: Inflammation at entheses and sacroiliac joints leading to progressive spinal fusion if unmanaged
Strength work: Back: Spinal Erectors; Core: Transverse Abdominis; Back: Traps: Lower; extension-biased strength
Stretching: Spine; Chest; Hips: Flexors; daily spinal extension and rotation is essential
Massage: Back: Upper Back; Back: QL
Also worth doing: Chest expansion and breathing exercises; swimming
What the evidence says: Exercise is the cornerstone of management alongside medication - it is one of the few conditions where daily stretching genuinely changes long-term structural outcome.
The names above are the Targets qFIT tracks —
the Muscle Guide explains what each one does, and
Quick Add switches on the Exercises you
already have.
The qFIT routine for this
Ready-made routineInflammatory Arthritis (RA, PsA & Axial SpA)
qFIT already has this one built. It runs massage first, then stretching, then
strength — the order that works on a body that is already sore — and every
activity in it carries the reason it is there.
The button below opens your Checklist with this routine already selected, so instead
of your whole list you land on just its Categories, Targets
and Exercises, each with its checkbox, ready to tick as you work through
them.
Have more than one problem? Tick yours under My Problems on
My Profile and your Checklist's Routine list gains
Recommended for my problems — every routine for the problems you picked, merged
into one. Your picks stay private; that filter is the only thing they feed.
Get it checked if…
Back pain in an under-45 that improves with exercise and worsens with rest, with morning stiffness over 30 minutes, needs a rheumatology referral - this is the pattern that gets missed for years
And whatever the body part: chest pain or unusual breathlessness on
exertion; a fever alongside the pain; unexplained weight loss; pain that is constant and
unrelated to how you move; new numbness, weakness or loss of bladder or bowel control; or
one calf that is swollen, warm and painful. Any of those, stop and get assessed.
How it usually goes
Exercise is central rather than adjunctive here - daily spinal mobility work maintains range and reduces symptoms, and it is one of the few conditions where the exercise genuinely relieves the pain rather than just building capacity. Modern biological treatments have transformed outcomes for those with active disease. The delay to diagnosis remains the biggest problem: back pain in someone under forty that is worse with rest, wakes them at night and improves with movement is worth raising specifically.
Prevalence basis: Rheumatology epidemiology
Others the same routine covers
These share the Inflammatory Arthritis (RA, PsA & Axial SpA) routine, so the work is the same. If one of them also
sounds like you, that is a reason to expect more from it, not less.
This is general information, not a diagnosis, and it cannot examine you.
If it matches you, use it to ask better questions of a clinician rather than to replace one.