About one-third of people with ankylosing spondylitis (AS) experience shoulder pain. But shoulder pain on its own isn’t a sign of AS. Conservative treatments are usually effective in managing shoulder pain from AS.

Ankylosing spondylitis (AS) is an autoimmune disease that causes pain and inflammation of your joints.

“Ankylosing” comes from the word “ankylosis,” which refers to atypical stiffening of the joints and loss of mobility due to the fusion of bones. “Spondylitis” refers to inflammation of your vertebrae (back bones).

AS primarily causes pain and stiffness in your lower back but can also lead to inflammation in other parts of your spine or other joints, such as your shoulders. About 30% of people with AS have shoulder involvement.

People with shoulder pain from AS usually also have lower back pain.

Keep reading to learn more about how AS affects your shoulders and how you can manage your pain.

AS is an autoimmune disease. Researchers don’t know exactly what causes it, but it’s thought that your genetics and environmental factors both play a role.

The shoulders are the second most affected joint outside of the spine in people with ankylosing spondylitis.

According to the Spondylitis Association of America, shoulder involvement is usually mild. It can cause symptoms such as:

  • swelling
  • stiffness
  • joint tenderness
  • loss of range of motion

It’s likely that AS will affect only one of your shoulders or affect one shoulder more than the other. Symptoms generally alternate between flare-ups where they’re more severe and periods where they go away or are greatly reduced. The progression of symptoms can vary significantly between people.

In a 2021 study, researchers found that people self-reported flare-ups an average of once every 35.32 days and that they lasted an average of 4.3 days.

Most people with shoulder pain from AS also have lower back pain. Lower back pain and stiffness tend to develop gradually. These symptoms tend to get worse during periods of inactivity.

Other joints that AS can affect include:

  • fingers or toes
  • upper back or neck
  • ribs
  • hips
  • knees
  • elbows
  • jaw

Shoulder pain and stiffness are common symptoms of AS. But they’re unlikely to be symptoms without lower back pain. According to the Spondylitis Association of America, pain starts in joints outside the spine in a minority of people.

More than 90% of people with AS have a gene called HLA-B27. But this gene is also common in the general population, and most people who carry it never develop AS. If your doctor suspects you might have AS, they may recommend a blood test to see if you’re carrying the HLA-B27 gene.

In a 2020 study, researchers found that people with AS are at an increased risk of adhesive capsulitis, also known as frozen shoulder. It’s a condition characterized by the thickening of the connective tissue around your shoulder, which leads to stiffness and pain.

In rare cases, AS may happen at the same time as other conditions that may cause shoulder pain.

In a 2018 case study, a 54-year-old man had limited motion through his shoulder and pelvis. Doctors diagnosed AS and polymyalgia rheumatica. Corticosteroids improved his symptoms.

In a 2022 case study, an 18-year-old former tennis player had undergone surgery on each shoulder and had a history of complex regional pain syndrome and Ehler-Danlos syndrome. Doctors eventually diagnosed AS along with Parsonage-Turner syndrome. Her pain improved with physical therapy and joint injections.

Ankylosing spondylitis and other conditions and symptoms

Fatigue is a common symptom of AS and some medications that are used to treat it.

People often develop AS along with other autoimmune diseases, such as:

Roughly a third of people with AS also have anterior uveitis, which can cause blurred vision and other changes to your vision.

Learn more about AS and your eyes.

Most people with AS can manage their pain with conservative options. People often find relief with treatments such as:

Doctors often recommend low impact exercises, such as yoga or swimming, to help manage AS.

In a small 2021 study, researchers found that yoga helped reduce pain in a group of 24 people with AS.

Surgery

In rare cases, doctors recommend surgery if all other treatment options fail to give you symptom relief.

In a 2021 case study, a 36-year-old man with AS had 8 years of shoulder pain and restricted movement. They treated him with a shoulder joint replacement, which resulted in good joint function.

AS is an autoimmune condition that usually causes lower back stiffness and loss of range of motion. It can also affect other joints, such as your shoulders. Roughly a third of people with ankylosing spondylitis have shoulder involvement.

Most people can manage their shoulder pain at home with medications and lifestyle changes. In rare cases, you may need surgery if conservative treatments aren’t effective.