Short answer · Medically reviewed summary · Last updated: 2026-04-07
Ankylosing Spondylitis is primarily diagnosed through a combination of clinical physical examinations, imaging studies like X-rays or MRIs, and blood tests to check for markers of inflammation and the HLA-B27 gene. Because symptoms often overlap with common mechanical back pain, the diagnostic process requires a rheumatologist to identify specific patterns of inflammatory spinal involvement that distinguish Ankylosing Spondylitis from other conditions. How do doctors officially diagnose Ankylosing Spondylitis? The diagnostic process for Ankylosing Spondylitis is often described as a "diagnostic odyssey" because early symptoms, such as chronic back pain and stiffness, are frequently dismissed as simple musculoskeletal strain.
22 people with Ankylosing Spondylitis have shared their first-person experience on this question at DiseaseMaps.
How is Ankylosing Spondylitis diagnosed?
How Ankylosing Spondylitis is diagnosed: tests, specialists and the diagnostic journey, told by patients and reviewed against medical sources.
Ankylosing Spondylitis is primarily diagnosed through a combination of clinical physical examinations, imaging studies like X-rays or MRIs, and blood tests to check for markers of inflammation and the HLA-B27 gene. Because symptoms often overlap with common mechanical back pain, the diagnostic process requires a rheumatologist to identify specific patterns of inflammatory spinal involvement that distinguish Ankylosing Spondylitis from other conditions.
How do doctors officially diagnose Ankylosing Spondylitis?
The diagnostic process for Ankylosing Spondylitis is often described as a "diagnostic odyssey" because early symptoms, such as chronic back pain and stiffness, are frequently dismissed as simple musculoskeletal strain. A rheumatologist typically follows the Assessment of SpondyloArthritis international Society (ASAS) criteria, which look for chronic back pain lasting more than three months in individuals under age 45. The diagnosis relies on evidence of sacroiliitis—inflammation of the joints connecting the spine to the pelvis—which is the hallmark of Ankylosing Spondylitis.
What tests are used to confirm Ankylosing Spondylitis?
To reach a definitive diagnosis, clinicians utilize a multi-modal approach to rule out other causes of pain and confirm systemic inflammation. Key diagnostic tools include:
- Imaging: X-rays of the sacroiliac joints are often the first step, though MRI is significantly more sensitive for detecting early-stage Ankylosing Spondylitis before permanent damage occurs.
- Genetic Testing: Testing for the HLA-B27 gene can support a diagnosis, as approximately 80-90% of individuals with Ankylosing Spondylitis in certain populations carry this marker, though it is not diagnostic on its own.
- Blood Tests: Tests for C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) help identify systemic inflammation within the immune system.
- Physical Examination: Evaluation of chest expansion, spinal mobility, and specific provocation tests (like the FABER test) to assess joint function.
Why is there often a delay in diagnosing Ankylosing Spondylitis?
It is medically validated that the journey to an Ankylosing Spondylitis diagnosis can take several years. This delay occurs because the condition is often confused with mechanical back pain, fibromyalgia, or sports injuries. Many patients feel frustrated by the "invisible" nature of their pain, but it is important to remember that this is a systemic disease affecting the skeletal, muscular, and digestive systems, not just a localized injury. With over 2,109 members in the DiseaseMaps.org community, you are not alone in this experience; many others have navigated this exact path before finding the right care.
When should you consult a specialist?
If you suspect you have Ankylosing Spondylitis and your primary care physician has not provided answers, it is critical to request a referral to a rheumatologist. A rheumatologist has the specialized training to distinguish between mechanical back pain and inflammatory spondyloarthritis. Early intervention is vital to manage the inflammation and preserve spinal mobility.
Next steps
- Request a referral to a board-certified rheumatologist.
- Keep a symptom diary tracking your stiffness levels, time of day symptoms are worst, and how exercise impacts your pain.
- Join the DiseaseMaps.org community to connect with others who have navigated the diagnosis of Ankylosing Spondylitis.
- Prepare a list of your family medical history, as genetic factors play a significant role in this condition.
Medical disclaimer: This information is for educational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.
References
- NIH Genetic and Rare Diseases (GARD) Information Center: Ankylosing Spondylitis.
- Orphanet (ORPHA: 831): Ankylosing Spondylitis.
- Spondylitis Association of America: Diagnostic Criteria and Testing.
- OMIM (Online Mendelian Inheritance in Man): Ankylosing Spondylitis entry #106300.
Posted Mar 4, 2017 by Denise 450
Symptoms
Early signs and symptoms of ankylosing spondylitis might include pain and stiffness in your lower back and hips, especially in the morning and after periods of inactivity. Neck pain and fatigue also are common. Over time, symptoms might worsen, improve or stop at irregular intervals.
The areas most commonly affected are:
The joint between the base of your spine and your pelvis (sacroiliac)
The vertebrae in your lower back
The places where your tendons and ligaments attach to bones (entheses), mainly in your spine, but sometimes along the back of your heel
The cartilage between your breastbone and ribs
Your hip and shoulder joints
When to see a doctor
Seek medical attention if you have low back or buttock pain that came on slowly, is worse in the morning or awakens you from your sleep in the second half of the night — particularly if this pain improves with exercise and worsens with rest. See an eye specialist (ophthalmologist) immediately if you develop a painful red eye, severe light sensitivity or blurred vision.
A rheumatologist is commonly the type of physician who will diagnose ankylosing spondylitis (AS), since they are doctors who are specially trained in diagnosing and treating disorders that affect the joints, muscles, tendons, ligaments, connective tissue, and bones.
Posted Mar 4, 2017 by kat1 1050
Posted Mar 5, 2017 by Heather 1120
Posted May 17, 2017 by Shannon 1050
Posted May 17, 2017 by Keli 1050
Posted May 18, 2017 by Karlie 1150
Posted May 18, 2017 by kelly cannell 500
Posted May 19, 2017 by Kylie Frost 2120
Posted May 19, 2017 by Tamra 1750
Posted Aug 31, 2017 by BigStu111 12832
Posted Sep 6, 2017 by Daniel Wilson 2010
Posted Sep 7, 2017 by Luciano Scariano 2600
MRI
X-rays
Medical check
Medical performance tests
Posted Sep 7, 2017 by Carol 600
Posted Sep 10, 2017 by Sal 4050
Posted Sep 21, 2017 by Rana Navid Anwaar Khan 3945
RISONANAZA magnetica
Raggi x
Ves
Pcr
Protidogramma
Posted Oct 1, 2017 by Silvia 2500
Unfortunately, depending on so many factors as the health system of the country, doctors, patients, access to investigation and many other reason can lead to years of misdiagnose.
Doctors working with specialists as Rhumatologist are necessary.
Usually an X-Ray will be needed, but sadly only once the damaged are irreversible this way could help for diagnose, this is why in nowadays MRI are much more efficient to help early diagnose as they can help see inflammation at an early stage before bone ossification.
Also one of the criteria that can help is the test of the gene HLA-B27. If positive that can reinforce the supposition of the illness but it should by no means exclude the illness! As it is known by now that more than 100 genes can be related to AS and that many patients who have AS don't have HLA-B27.
But a few questions like:
did the pain last more than 3 months?
did it started before 45 years old?
did the pain get better or worse with exercice?
did the pain wakes up during the night?
did the pain came gradually over time?
Can already help to understand if the patient might be suffering from an inflammatory condition and help to actually take the right step towards the right direction for a diagnose.
Posted Feb 16, 2018 by Laeti 3570
Posted May 31, 2018 by Colleen 2550
Posted Aug 10, 2017 by Andressa 1050
Posted Aug 14, 2017 by Luz 901
Posted Aug 15, 2017 by Adriana 1000
