Table of ContentsView AllTable of ContentsPhysical ExamBlood TestsGenetic TestingImagingConfirming a DiagnosisFrequently Asked QuestionsNext in Ankylosing Spondylitis GuideIs Ankylosing Spondylitis Genetic?
Table of ContentsView All
View All
Table of Contents
Physical Exam
Blood Tests
Genetic Testing
Imaging
Confirming a Diagnosis
Frequently Asked Questions
Next in Ankylosing Spondylitis Guide
If you experiencelow back painthat lasts three or more months, you may have a type ofaxial spondylitis(axial SpA) calledankylosing spondylitis(AS). AS is an aggressive autoimmune condition, so getting an early diagnosis and starting treatment immediately is crucial.
The tests used to diagnose ankylosing spondylitis include a physical examination, a medical history, blood tests, genetic testing, and imaging.
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Symptoms of AS typically start in the late teens to mid-30s, but anyone can develop it, including children. But because symptoms start slowly, they are often ignored or mistaken for other health problems. A 2015 reports found the average diagnostic delay for axial SpA is eight years.
It is not unusual for people with AS to see multiple healthcare providers to manage the back pain and stiffness that turns out to be AS. These medical professionals can include primary care providers, orthopedists (specialists in conditions of the musculoskeletal system), physical therapists, and chiropractors.
But the type of healthcare provider who can best diagnose AS is arheumatologist—a doctor with specialized training in musculoskeletal andautoimmune diseaseslike AS. If you have symptoms suggestive of AS, make an appointment to see a rheumatologist or ask your primary healthcare provider for a referral.
This article covers tests to diagnose AS, including physical and neurological exams, blood work, genetic testing, and imaging.
Ankylosing Spondylitis Physical Exam
A physical examination of AS typically starts with a thorough review of your medical and family history.
Your medical history looks at whether your back pain is mechanical or inflammatory. According to the Spondylitis Association of America, mechanical back pain occurs due to physical changes in the back.It is often the result of everyday activities like lifting heavy objects, incorrect posture, or poor sleep positions.
Causes of Back Pain and Treatment Options
On the other hand, inflammatory back pain related to AS is persistent, lasting for more than three months, affects people under age 35, and worsens after periods of inactivity.Inflammatory back pain will improve with movement, exercise, andnonsteroidal anti-inflammatory drugs(NSAIDs) such as ibuprofen.
In addition to understanding the nature of your back pain, your healthcare provider will want to know when symptoms started and what worsens and improves them. They also want to know about systemic symptoms (those that affect the entire body) and other joint pain in the neck, hips, shoulders, arms, and legs.
It is helpful to share every detail about your symptoms and overall health to help the healthcare provider make an accurate diagnosis.
TheHLA-B27 gene, which can lead to AS, is inherited. Moreover, family and twin studies have shown that AS has a strong genetic component.You should inform your healthcare provider if AS or other autoimmune diseases run in your family.
Once the healthcare provider has gotten information about your medical and family history, they will want to perform a thorough physical and neurological examination.
You will be asked to bend your back and hips in different directions during the physical exam to check for stiffness and pain. They might also push on some body areas to look for tender spots.
Since breathing difficulty is a sign of severe AS, the healthcare provider will also check your breathing.Breathing troubles in AS result from lung scarring due to inflammation, the upper body arching forward, and the chest wall stiffening.
The neurological exam assesses sensory and motor functions, including reflexes and muscle strength.Your healthcare provider will also review your other neurological symptoms, such as nerve pain, numbness, tingling, muscle weakness or spasms, and bowel and bladder dysfunction.
Blood Tests for Ankylosing Spondylitis
Blood work can look for signs ofinflammationsuggestive of AS. It is also done to rule out other conditions. Blood tests are not enough to confirm AS, but they help the healthcare provider make sense of your symptoms.
There are no specific tests to confirm AS, but certain blood tests can check for inflammatory markers and rule out other conditions that cause similar symptoms.
The following blood tests may be ordered if AS is suspected:
Genetic Testing for Ankylosing Spondylitis
A genetic blood test can be requested to see if you carry the HLA-B27 gene. According to a 2018report, this gene is only found in 8% of the general population.HLA-B27 is present in 90% of people with AS.
Testing positive for HLA-B27 does not mean you will go on to develop AS. Only around 5% to 6% of people with the gene will develop AS, according to a 2019report in the journalBone Research.
If you carry the HLA-B27 gene, your healthcare provider is more likely to suspect AS. This gene is also linked to more severe AS symptoms, such as eye inflammation and a condition calleduveitis(inflammation of the middle layer of tissue in the eye wall).
What Is the HLA-B27 Test for Ankylosing Spondylitis?
Ankylosing Spondylitis Imaging Tests
Different imaging studies can help with making a diagnosis of AS, includingconventional radiology(X-rays),magnetic resonance imaging(MRI),computed tomography(CT), and ultrasound.X-rays are standard for diagnosing AS, while a CT, MRI, or ultrasound scan might be requested to evaluate bone and soft tissues of the spine in greater detail.
If your healthcare provider requests imaging, they might be looking for the following signs of AS:
Your healthcare provider might use X-rays and MRI to track AS disease progression or to look for fractures or joint damage.
Confirming an Ankylosing Spondylitis Diagnosis
Your healthcare provider will rely on your physical and neurological exams, symptom history, imaging results, and blood work to diagnose AS.
According to a 2020Rheumatologyreport, a healthcare provider can make a diagnosis of AS based on specific criteria, which include:
If you have experienced inflammatory back pain for at least three or more months, along with other characteristics that are part of AS diagnostic criteria, your healthcare provider will likely diagnose you with AS.
Summary
Ankylosing spondylitis is an autoimmune disease that occurs when the immune system malfunctions and attacks healthy tissues—mainly the small bones of the spine. AS is an aggressive condition and early diagnosis is crucial to reducing spine complications, such as spinal fusion, fractures, and abnormal curvatures.
If you experience signs and symptoms of AS, like pain and stiffness in the low back and hips, reach out to a healthcare provider so they can request testing to determine the cause. Tests used to diagnose AS include physical and neurological exams, blood tests, genetic testing, and imaging.
A diagnosis of AS is typically made based on symptoms, blood work, imaging results, and HLA-B27 positivity.
A Word From Verywell
Ankylosing spondylitis is a lifelong condition. There is no cure for the disease, but it is treatable and manageable.
You will have many options for treating your condition, which can reduce symptoms and prevent disease progression. Taking your medications as prescribed is crucial to slowing down the disease’s effects on you, keeping you moving and independent, and maintaining a good quality of life.
In addition to following your treatment plan, you should see a rheumatologist regularly. And make sure you speak up if your treatment plan isn’t managing your symptoms adequately.
Frequently Asked QuestionsThe earliest signs of ankylosing spondylitis are pain and stiffness of the low back and hips, especially in the morning and after periods of inactivity. You might also experience neck pain and fatigue. Over time, these symptoms will worsen or improve during flare-ups (worsening disease) and remission (no symptoms).Learn MoreWhat Are the Early Signs of Ankylosing Spondylitis?If you experience ankylosing spondylitis symptoms, a primary care provider might refer you to a rheumatologist. A rheumatologist is specially trained in diagnosing and treating disorders like AS that affect the joints, muscles, connective tissues, and bones.Learn MoreWhen to See a Rheumatologist for Your Back PainAfter receiving an ankylosing spondylitis diagnosis, you will want to work with your healthcare provider to create a treatment plan. You will be prescribed medications and be given information on lifestyle habits to help manage symptoms, such as diet changes, exercise, and adaptive aids to reduce joint stress.Learn MoreWhat Are Your Treatment Options for Advanced Ankylosing Spondylitis?
The earliest signs of ankylosing spondylitis are pain and stiffness of the low back and hips, especially in the morning and after periods of inactivity. You might also experience neck pain and fatigue. Over time, these symptoms will worsen or improve during flare-ups (worsening disease) and remission (no symptoms).Learn MoreWhat Are the Early Signs of Ankylosing Spondylitis?
The earliest signs of ankylosing spondylitis are pain and stiffness of the low back and hips, especially in the morning and after periods of inactivity. You might also experience neck pain and fatigue. Over time, these symptoms will worsen or improve during flare-ups (worsening disease) and remission (no symptoms).
Learn MoreWhat Are the Early Signs of Ankylosing Spondylitis?
If you experience ankylosing spondylitis symptoms, a primary care provider might refer you to a rheumatologist. A rheumatologist is specially trained in diagnosing and treating disorders like AS that affect the joints, muscles, connective tissues, and bones.Learn MoreWhen to See a Rheumatologist for Your Back Pain
If you experience ankylosing spondylitis symptoms, a primary care provider might refer you to a rheumatologist. A rheumatologist is specially trained in diagnosing and treating disorders like AS that affect the joints, muscles, connective tissues, and bones.
Learn MoreWhen to See a Rheumatologist for Your Back Pain
After receiving an ankylosing spondylitis diagnosis, you will want to work with your healthcare provider to create a treatment plan. You will be prescribed medications and be given information on lifestyle habits to help manage symptoms, such as diet changes, exercise, and adaptive aids to reduce joint stress.Learn MoreWhat Are Your Treatment Options for Advanced Ankylosing Spondylitis?
After receiving an ankylosing spondylitis diagnosis, you will want to work with your healthcare provider to create a treatment plan. You will be prescribed medications and be given information on lifestyle habits to help manage symptoms, such as diet changes, exercise, and adaptive aids to reduce joint stress.
Learn MoreWhat Are Your Treatment Options for Advanced Ankylosing Spondylitis?
10 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Seo MR, Baek HL, Yoon HH, et al.Delayed diagnosis is linked to worse outcomes and unfavourable treatment responses in patients with axial spondyloarthritis.Clin Rheumatol. 2015;34(8):1397-1405. doi:10.1007/s10067-014-2768-ySpondylitis Association of America.Inflammatory vs. mechanical back pain.Tsui FW, Tsui HW, Akram A, Haroon N, Inman RD.The genetic basis of ankylosing spondylitis: new insights into disease pathogenesis.Appl Clin Genet. 2014;7:105-115. Published 2014 May 22. doi:10.2147/TACG.S37325Berdal G, Halvorsen S, van der Heijde D, Mowe M, Dagfinrud H.Restrictive pulmonary function is more prevalent in patients with ankylosing spondylitis than in matched population controls and is associated with impaired spinal mobility: a comparative study.Arthritis Res Ther. 2012;14(1):R19. doi:10.1186/ar3699Zhu W, He X, Cheng K, et al.Ankylosing spondylitis: etiology, pathogenesis, and treatments.Bone Res. 2019;7:22. doi:10.1038/s41413-019-0057-8Gensler L. Spondylitis Association of America.Blood work in ankylosing spondylitis.Ingegnoli F, Castelli R, Gualtierotti R.Rheumatoid factors: clinical applications.Dis Markers. 2013;35(6):727-734. doi:10.1155/2013/726598Akassou A, Bakri Y.Does HLA-B27 status influence ankylosing spondylitis phenotype?Clin Med Insights Arthritis Musculoskelet Disord. 2018;11:1179544117751627. doi:10.1177/1179544117751627KhmelinskiiN, Regel A, Baraliakos X.The role of imaging in diagnosing axial spondyloarthritis.Front Med (Lausanne). 2018;5:106. doi:10.3389/fmed.2018.00106Poddubnyy D.Classification vs diagnostic criteria: the challenge of diagnosing axial spondyloarthritis.Rheumatology (Oxford). 2020;59(Suppl4):iv6-iv17. doi:10.1093/rheumatology/keaa250
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Seo MR, Baek HL, Yoon HH, et al.Delayed diagnosis is linked to worse outcomes and unfavourable treatment responses in patients with axial spondyloarthritis.Clin Rheumatol. 2015;34(8):1397-1405. doi:10.1007/s10067-014-2768-ySpondylitis Association of America.Inflammatory vs. mechanical back pain.Tsui FW, Tsui HW, Akram A, Haroon N, Inman RD.The genetic basis of ankylosing spondylitis: new insights into disease pathogenesis.Appl Clin Genet. 2014;7:105-115. Published 2014 May 22. doi:10.2147/TACG.S37325Berdal G, Halvorsen S, van der Heijde D, Mowe M, Dagfinrud H.Restrictive pulmonary function is more prevalent in patients with ankylosing spondylitis than in matched population controls and is associated with impaired spinal mobility: a comparative study.Arthritis Res Ther. 2012;14(1):R19. doi:10.1186/ar3699Zhu W, He X, Cheng K, et al.Ankylosing spondylitis: etiology, pathogenesis, and treatments.Bone Res. 2019;7:22. doi:10.1038/s41413-019-0057-8Gensler L. Spondylitis Association of America.Blood work in ankylosing spondylitis.Ingegnoli F, Castelli R, Gualtierotti R.Rheumatoid factors: clinical applications.Dis Markers. 2013;35(6):727-734. doi:10.1155/2013/726598Akassou A, Bakri Y.Does HLA-B27 status influence ankylosing spondylitis phenotype?Clin Med Insights Arthritis Musculoskelet Disord. 2018;11:1179544117751627. doi:10.1177/1179544117751627KhmelinskiiN, Regel A, Baraliakos X.The role of imaging in diagnosing axial spondyloarthritis.Front Med (Lausanne). 2018;5:106. doi:10.3389/fmed.2018.00106Poddubnyy D.Classification vs diagnostic criteria: the challenge of diagnosing axial spondyloarthritis.Rheumatology (Oxford). 2020;59(Suppl4):iv6-iv17. doi:10.1093/rheumatology/keaa250
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Seo MR, Baek HL, Yoon HH, et al.Delayed diagnosis is linked to worse outcomes and unfavourable treatment responses in patients with axial spondyloarthritis.Clin Rheumatol. 2015;34(8):1397-1405. doi:10.1007/s10067-014-2768-ySpondylitis Association of America.Inflammatory vs. mechanical back pain.Tsui FW, Tsui HW, Akram A, Haroon N, Inman RD.The genetic basis of ankylosing spondylitis: new insights into disease pathogenesis.Appl Clin Genet. 2014;7:105-115. Published 2014 May 22. doi:10.2147/TACG.S37325Berdal G, Halvorsen S, van der Heijde D, Mowe M, Dagfinrud H.Restrictive pulmonary function is more prevalent in patients with ankylosing spondylitis than in matched population controls and is associated with impaired spinal mobility: a comparative study.Arthritis Res Ther. 2012;14(1):R19. doi:10.1186/ar3699Zhu W, He X, Cheng K, et al.Ankylosing spondylitis: etiology, pathogenesis, and treatments.Bone Res. 2019;7:22. doi:10.1038/s41413-019-0057-8Gensler L. Spondylitis Association of America.Blood work in ankylosing spondylitis.Ingegnoli F, Castelli R, Gualtierotti R.Rheumatoid factors: clinical applications.Dis Markers. 2013;35(6):727-734. doi:10.1155/2013/726598Akassou A, Bakri Y.Does HLA-B27 status influence ankylosing spondylitis phenotype?Clin Med Insights Arthritis Musculoskelet Disord. 2018;11:1179544117751627. doi:10.1177/1179544117751627KhmelinskiiN, Regel A, Baraliakos X.The role of imaging in diagnosing axial spondyloarthritis.Front Med (Lausanne). 2018;5:106. doi:10.3389/fmed.2018.00106Poddubnyy D.Classification vs diagnostic criteria: the challenge of diagnosing axial spondyloarthritis.Rheumatology (Oxford). 2020;59(Suppl4):iv6-iv17. doi:10.1093/rheumatology/keaa250
Seo MR, Baek HL, Yoon HH, et al.Delayed diagnosis is linked to worse outcomes and unfavourable treatment responses in patients with axial spondyloarthritis.Clin Rheumatol. 2015;34(8):1397-1405. doi:10.1007/s10067-014-2768-y
Spondylitis Association of America.Inflammatory vs. mechanical back pain.
Tsui FW, Tsui HW, Akram A, Haroon N, Inman RD.The genetic basis of ankylosing spondylitis: new insights into disease pathogenesis.Appl Clin Genet. 2014;7:105-115. Published 2014 May 22. doi:10.2147/TACG.S37325
Berdal G, Halvorsen S, van der Heijde D, Mowe M, Dagfinrud H.Restrictive pulmonary function is more prevalent in patients with ankylosing spondylitis than in matched population controls and is associated with impaired spinal mobility: a comparative study.Arthritis Res Ther. 2012;14(1):R19. doi:10.1186/ar3699
Zhu W, He X, Cheng K, et al.Ankylosing spondylitis: etiology, pathogenesis, and treatments.Bone Res. 2019;7:22. doi:10.1038/s41413-019-0057-8
Gensler L. Spondylitis Association of America.Blood work in ankylosing spondylitis.
Ingegnoli F, Castelli R, Gualtierotti R.Rheumatoid factors: clinical applications.Dis Markers. 2013;35(6):727-734. doi:10.1155/2013/726598
Akassou A, Bakri Y.Does HLA-B27 status influence ankylosing spondylitis phenotype?Clin Med Insights Arthritis Musculoskelet Disord. 2018;11:1179544117751627. doi:10.1177/1179544117751627
KhmelinskiiN, Regel A, Baraliakos X.The role of imaging in diagnosing axial spondyloarthritis.Front Med (Lausanne). 2018;5:106. doi:10.3389/fmed.2018.00106
Poddubnyy D.Classification vs diagnostic criteria: the challenge of diagnosing axial spondyloarthritis.Rheumatology (Oxford). 2020;59(Suppl4):iv6-iv17. doi:10.1093/rheumatology/keaa250
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