What Are the Symptoms of Ankylosing Spondylitis?

Bothersome back pain and joint stiffness are good reasons to see a healthcare provider, regardless of the cause.

Ankylosing spondylitis (AS) is an inflammatory condition of the joints and ligaments in the spine. AS is a form of arthritis and can sometimes lead to the fusion of bones along the spine.

Not everyone with AS experiences the condition the same way. Symptoms typically surface between ages 17 and 45 but may also affect younger children and older adults. Likewise, the severity of the disease ranges from mild to severe, and people may have periods during which their symptoms flare up and then improve.

Some people are unfamiliar with the disease, let alone the signs and symptoms that may lead to an AS diagnosis. It's important to identify AS early to prevent complications. Here are some of the symptoms people with AS may exhibit.

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Difficulty Moving Your Joints

The identifying feature of AS is when joints that were once able to move freely in the spine become immobile. Other than the spine, this change may feel like stiffness or pain in the following joints:

  • Sacroiliac (SI) joint (the joint that connects the pelvis and lower spine)
  • Peripheral joints (knee, ankle, shoulder, wrist, elbow)
  • Joints of the fingers and toes

As you might imagine, as the joints begin to lose mobility, other parts of the body are affected. "That stiffness results in a reduced range of motion that may cause other joints that are functioning to compensate," Anand Veeravagu, MD, assistant professor of neurosurgery and director of minimally invasive neurospine surgery at Stanford Medicine.

This can lead to more pain and arthritis in the functioning joints. People with AS may have rib pain and tenderness, for example, where the ribs attach to the spine.

Back Pain

Back pain is common among people with ankylosing spondylitis. More specifically, the type of back pain that people with AS experience generally includes four of the five following characteristics:

  • Typically strikes people before the age of 40
  • Comes on slowly
  • Improves with exercise
  • Does not improve with rest
  • Causes pain at night, which improves upon waking

Some people may have mild episodes that come and go, while others will develop chronic pain.

Poor Posture

As ankylosing spondylitis progresses, more bones can be fused, including those in the cervical spine (top of the spine, near your neck).

This puts the spine in a flexed position, explained Nick Shamie, MD, chief of orthopedic spine surgery and professor of orthopedic surgery and neurosurgery at UCLA School of Medicine, and ankylosing spondylitis patients can end up with their bones fused in this position.

"If you look down at your feet right now and imagine your neck was locked in that position, it would make life very difficult, not only for mobility but even eating, because...you can't open your mouth as well," said Dr. Shamie.

Stooped posture that has frozen that way is one of the biggest reasons surgery might become necessary for ankylosing spondylitis patients, said Dr. Shamie.

Difficulty Breathing

Breathing problems are a possible complication for AS. If the vertebrae and ribs fuse to the spine, this can restrict the movement of your chest and make it difficult to take deep breaths.

Smoking is a risk factor for disease progression in people with AS. It is recommended that people who smoke and have AS quit smoking to avoid further complications.

Eye Inflammation

Ankylosing spondylitis can lead to uveitis, or inflammation of the eye. Roughly 25–35% of people with AS will develop this complication. Uveitis may cause:

  • Eye pain
  • Vision changes
  • Floaters (spots that float across your vision)
  • Blurry vision
  • Light sensitivity

GI Symptoms

Given the role of inflammation, it may not be surprising to learn that ankylosing spondylitis can also affect the gastrointestinal (GI) tract. AS can cause symptoms such as abdominal pain and diarrhea.

If you have AS, developing inflammatory bowel disease (IBD) is common. Up to half of people with AS develop IBD. IBD includes conditions such as Crohn's disease and ulcerative colitis.

Skin Rash

About one in 10 people with ankylosing spondylitis also develop psoriasis. These itchy, scaly patches may be limited to small areas of the skin or more extensive. The rashes that people with AS develop should not be confused with psoriatic arthritis, a different condition.


Fatigue is one of the main symptoms of ankylosing spondylitis, occurring in 50–70% of people with AS.

Fatigue can lead to poor quality of life for people with AS. It isn't easily treatable because it's a poorly understood symptom.

How Ankylosing Spondylitis Is Diagnosed

Symptoms are an important piece of the puzzle. Chronic back pain that improves with exercise and worsens when resting is among the signs that it could be AS.

If a patient shows up with back pain and stiffness, a healthcare provider will often do a physical exam and order blood tests and x-ray images. One of the early indicators of ankylosis spondylitis on x-ray is inflammation of the sacroiliac joints—where the spine and the pelvis meet.

Some people may also have a genetic marker in their blood called HLA-B27, which some ankylosing spondylitis patients will be positive for. About 5–6% of people with the HLA-B27 gene also have AS.

Ultimately, if a patient is diagnosed with ankylosing spondylitis, the goal is to reduce pain and the inflammatory process while preserving as much movement as possible. Early diagnosis can help ward off some of the complications of AS.

A Quick Review

Ankylosing spondylitis is an inflammatory, arthritic condition that can impact multiple joints—mostly your back. Over time, your spine may become stiff, limiting your ability to move your back. You may experience pain and stiffness in other joints as well.

On top of joint issues, you may also experience poor posture, difficulty breathing, uveitis, psoriasis, GI symptoms, and fatigue. If you are experiencing any of these symptoms, talk to a healthcare provider so they can examine and treat you.

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8 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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