Ankylosing spondylitis is an inflammatory arthritis of the spine and sacroiliac joints. It is not wear and tear. It acts the opposite way to mechanical back pain. And the average patient waits years to be diagnosed.
What does ankylosing spondylitis back pain feel like?
The diagnosis turns on this one difference. It is also why the condition gets missed. Mechanical back pain is worse with activity and better with rest. Inflammatory back pain does the reverse.
- Worse with rest, better with movement. Patients get up and walk around at 4 a.m. because lying still hurts more than moving.
- Morning stiffness lasting more than 30 minutes, often much longer.
- Night pain, especially in the second half of the night.
- Onset before age 45, usually slow rather than after an injury.
- Substantial response to anti-inflammatories. It is often dramatic, and that is itself a clue.
- Alternating buttock pain, from the sacroiliac joints.
Picture someone in their twenties or thirties with months of back pain. It eases when they move and wakes them at night. That person does not have a disc problem. That pattern calls for investigation for spondyloarthritis.
What else does ankylosing spondylitis affect?
Axial spondyloarthritis is a whole-body disease. The signs outside the spine are often what confirm it:
- Enthesitis — inflammation where tendons attach to bone, most often the Achilles or the plantar fascia. Heel pain that will not quit in a young adult with back pain is a telling combination.
- Uveitis — a painful, red, light-sensitive eye. This is an eye emergency and needs to be seen the same day.
- Peripheral arthritis, usually on one side more than the other and in the legs.
- Psoriasis or inflammatory bowel disease, which belong to the same family of conditions.
- Dactylitis — a whole finger or toe swollen, not just one joint.
Why does ankylosing spondylitis take years to diagnose?
Several things work against you. Early disease often shows nothing on plain X-ray. The changes that give the condition its name take years to appear. And a normal film is often read as good news. MRI of the sacroiliac joints finds active inflammation far earlier, but someone has to order it.
HLA-B27 (a gene marker found by blood test) is associated with the condition. But you can have the disease without it, and having it does not mean you have the disease. Many people carry it and never get sick. And a real minority of patients test negative. It supports a diagnosis. It does not make or rule one out.
The most common error is blaming it on mechanical back pain in a young, otherwise healthy person. By the odds, that guess makes sense. When the inflammatory pattern above is present, it is wrong.
Our role, and where it ends
Ankylosing spondylitis is managed by rheumatology. Disease-modifying treatment changes the course of the disease. That means anti-inflammatories used properly, and biologic therapy aimed at TNF or IL-17 when they fit. That is a rheumatologist’s decision.
What we treat is the pain that sits alongside it. Long-standing spondyloarthritis causes mechanical problems of its own: sacroiliac joint pain, facet joint pain, and muscle strain from a stiffening spine. Those can be treated. But treating them does not replace disease control.
Your symptoms may fit the inflammatory pattern, and you may not have seen a rheumatologist. If so, telling you that is the most useful thing we will do at the first visit.
What can a pain doctor treat in ankylosing spondylitis?
- Sacroiliac joint pain are the joints most often involved. They are treatable with image-guided injection
- Facet joint pain from the extra load a stiffening spine puts on them
- Myofascial pain in the muscles working to make up for lost spine movement
- Physical therapy. In this condition it is part of treating the disease, not just an add-on. Keeping the spine moving and the chest able to expand matters
- Medication review, including how long-term anti-inflammatory use interacts with everything else
Movement is treatment here
In most back conditions exercise helps. In axial spondyloarthritis it is part of managing the disease. Regular movement work, back-bending exercise and keeping the chest able to expand make a measurable difference in long-term function. Stopping costs you.
That is worth knowing because the pain is often worst in the morning. That is exactly when the drive to move is lowest. Patients who understand why they are doing it tend to keep doing it.
To be assessed, call or text us. We are at 12174 Natural Bridge Rd, Suite 110, St. Louis, MO 63044.
What usually gets missed
The delay in diagnosing axial spondyloarthritis is measured in years. The reason: it looks like the mirror image of what doctors are trained to expect. Back pain that improves with exercise and worsens with rest seems unlikely to anyone screening for mechanical pain.
It is also missed more often in women. Women more often show up with neck and limb joint problems. They less often show the classic sacroiliitis (inflamed sacroiliac joints) on X-ray. A normal X-ray of the sacroiliac joints does not rule it out. Early disease shows on MRI long before it shows on plain film.
Does ankylosing spondylitis get worse over time?
Modern treatment has changed the course a great deal. The progressive spinal fusion (bones of the spine growing together) gave the condition its reputation. That is far less common in patients treated early with biologic therapy.
Our part is not the disease-modifying treatment. That belongs to rheumatology. Our part is the mechanical pain that lasts alongside it: facet and sacroiliac pain, and the effects of changed posture. That pain can be treated in its own right.
When this becomes urgent
Ankylosing spondylitis raises the risk of spinal fracture even after minor trauma, because a fused spine acts like a long bone. Any new pain after a fall, however small, needs imaging, not reassurance. Sudden visual change or eye pain suggests acute anterior uveitis (inflammation inside the front of the eye) and needs same-day ophthalmology review. New chest pain or breathlessness needs a check, given the links to the heart and lungs.
Common questions
Is ankylosing spondylitis the same as arthritis of the spine?
No, and the difference matters. Spinal osteoarthritis is degenerative wear. Ankylosing spondylitis is an inflammatory autoimmune condition that affects the whole body. It is treated completely differently.
My X-ray was normal. Does that rule it out?
No. X-ray changes take years to develop. Early disease often does not show on plain film. MRI of the sacroiliac joints finds active inflammation far earlier.
I tested negative for HLA-B27. Can I still have it?
Yes. A real minority of patients test negative. The test supports a diagnosis. It does not make or rule one out.
Will you prescribe a biologic?
No. That is a rheumatologist’s decision, and it should be. We treat the mechanical pain alongside the disease. And we will say plainly if you need a rheumatology referral you have not had.
Should I rest when it flares?
Usually the opposite. Inflammatory back pain is worse with rest and better with movement. That is why long rest tends to make a flare feel worse, not better.
What are the most common symptoms of ankylosing spondylitis?
Back pain that is worse with rest and better with movement. Morning stiffness lasting more than 30 minutes. Night pain, especially in the second half of the night. It usually starts slowly before age 45. Other signs point toward it too: buttock pain that switches sides, from the sacroiliac joints; heel pain where tendons attach to bone; and a painful, red, light-sensitive eye.
What can be mistaken for ankylosing spondylitis?
The mix-up usually runs the other way. Ankylosing spondylitis gets mistaken for plain mechanical back pain or a disc problem. That happens most in a young, otherwise healthy adult. Spinal osteoarthritis also gets confused with it. But that is degenerative wear, while ankylosing spondylitis is inflammatory. The pattern is the tell. Pain that eases when you move and wakes you at night is not a disc problem.
What does an ankylosing spondylitis flare feel like?
A flare brings the inflammatory pattern to the front. Lying still hurts more than moving, so people get up and walk around at 4 a.m. Morning stiffness runs well past 30 minutes. Pain wakes you in the second half of the night. Movement helps, not harms. That is why resting through a flare tends to make it feel worse. A red, painful eye needs same-day ophthalmology review.
Sources
- Navarro-Compán V et al. Axial spondyloarthritis. Lancet (London, England), 2025. PubMed 39798984
- Bittar M et al. Axial Spondyloarthritis: A Review. JAMA, 2025. PubMed 39630439
- Navarro-Compán V et al. Axial spondyloarthritis. Annals of the rheumatic diseases, 2021. PubMed 34615639
- Hwang MC et al. Ankylosing spondylitis risk factors: a systematic literature review. Clinical rheumatology, 2021. PubMed 33754220
Hurt in an accident? Start here.
You do not need a lawyer, a police report or a referral to be seen. Bring your symptoms and we will work out the rest.
Monday–Friday, 8:00 a.m. – 4:00 p.m. Same-day appointments are often available for new accident and injury patients.