Ankylosing spondylitis is an inflammatory arthritis that often affects the joints of the spine. It can also cause surprising symptoms that many people may not expect.

For some, ankylosing spondylitis causes unusual symptoms or ones people may not associate with the condition, such as issues with the eyes or lungs and fatigue.

This article reviews some of the uncommon or surprising ankylosing spondylitis symptoms. It also looks at other symptoms, treatment options, and more.

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Some evidence suggests that as many as 30–40% of people with ankylosing spondylitis develop issues with the eye known as acute anterior uveitis, or redness and inflammation in the front part of the eye.

A person may also experience pain, sensitivity to light, and blurry vision.

The condition may occur only once, or it may become chronic and recur several times.

Prescription eye drops may help improve the condition. Doctors may also recommend medications such as anti-inflammatories, disease-modifying antirheumatic drugs (DMARDs), and biologics.

Learn about ankylosing spondylitis and eye health.

Ankylosing spondylitis belongs to a family of conditions known as spondyloarthropathies. This family also includes inflammatory bowel disease-associated arthritis.

It may also make it more likely that a person will develop irritable bowel syndrome (IBS).

Learn about IBS.

Ankylosing spondylitis can cause inflammation and scar tissue to form in the lungs. This is known as pulmonary apical fibrosis. If it occurs, a person may feel constantly out of breath or have trouble breathing.

Physical therapy or medications to help with breathing may help treat this condition in people who develop it.

Ankylosing spondylitis involves the immune system attacking healthy parts of the body. This causes the production of widespread inflammation.

The chemicals associated with inflammation can make a person feel drained, tired, or generally fatigued.

Learn about treating fatigue in ankylosing spondylitis.

Enthesitis in people with ankylosing spondylitis may develop in the Achilles tendon. Enthesitis is inflammation of the enthesis, which is where the connective tissue enters the ligaments or tendons and bones.

When the tendon is in pain, it can make it more difficult to walk or move around in general.

A person may notice stiffness and pain in their feet that limits mobility.

Learn more about enthesitis.

Swelling can occur in several areas throughout the body, including the jaw. When it occurs, it can lead to pain and stiffness.

Jaw swelling and pain are known as temporomandibular joint (TMJ) disorder. According to a 2016 article, it can affect anywhere from 4–35% of people with ankylosing spondylitis.

Learn more about TMJ disorders.

Sleeping issues can occur due to pain and stiffness worsening or due to lack of movement.

Anywhere from 35–90% of people with axial spondyloarthritis, which includes ankylosing spondylitis, experience some form of sleep disturbance. This, in turn, can lead to decreased mood and lower energy levels.

Discover tips for getting better sleep with ankylosing spondylitis.

Loss of appetite may be an early sign of ankylosing spondylitis.

This may be a result of the inflammation, or it may be a side effect of medication or a result of depression.

For some, an early sign of ankylosing spondylitis could be a fever.

In a small 2017 study of 26 people with fever as an initial symptom of spondyloarthritis, 15.4% had ankylosing spondylitis.

Learn more about fever.

The most common symptom associated with ankylosing spondylitis is lower back pain or hip pain and stiffness.

A person may notice that their symptoms worsen with rest but improve with activity. This can mean that symptoms are worse in the mornings after waking up or after long periods of inactivity.

The severity of pain can vary from person to person. Some people may experience only occasional mild pain, while others may have much more severe pain that lingers for longer periods.

Learn more about ankylosing spondylitis symptoms.

A person with ankylosing spondylitis may benefit from a combination of medications, physical therapy, and lifestyle changes to manage symptoms.

A standard treatment for pain is the use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen.

Other medications a doctor may recommend to reduce pain and inflammation include:

  • DMARDs
  • immunosuppressants
  • corticosteroids
  • biologics

Treatments for uncommon symptoms of ankylosing spondylitis will vary based on what parts of the body are affected. It is best for a person to inform their doctor of any symptoms they experience so the doctor can advise on the most suitable treatment plan.

Learn more about ankylosing spondylitis treatments.

To reach an accurate diagnosis, a doctor may begin by asking questions about symptoms, taking a full medical history, and performing a physical exam.

If they suspect that a person may have ankylosing spondylitis, they may also order imaging tests, such as an X-ray or MRI.

Additionally, doctors may order blood work to check for inflammatory markers and potential genetic changes that may be linked to the condition.

Learn more about ankylosing spondylitis diagnosis.

Here are some frequently asked questions about ankylosing spondylitis.

What are the first symptoms of ankylosing spondylitis?

One of the earlier symptoms of ankylosing spondylitis can be a fever and a general feeling of being unwell. The most common symptom is lower back pain or pain and stiffness in the hip.

However, it is important to note that the initial symptoms of ankylosing spondylitis may be different for each individual.

What conditions have the same symptoms as ankylosing spondylitis?

Several conditions can mimic the pain and symptoms associated with ankylosing spondylitis, including:

  • reactive arthritis
  • chronic lower back pain
  • psoriatic arthritis
  • fibromyalgia
  • diffuse idiopathic skeletal hyperostosis (DISH)
  • enteropathic arthritis

If a person experiences symptoms of ankylosing spondylitis, it is best to contact a doctor for an accurate diagnosis and treatment plan.

Ankylosing spondylitis can cause different symptoms for each person. While it commonly causes lower back pain, various uncommon or surprising symptoms may also occur. Examples include acute anterior uveitis, pulmonary atypical fibrosis, fatigue, fever, and more.

It is best to inform a doctor if a person has concerns about ankylosing spondylitis or they begin to experience new symptoms. The doctor will be able to advise on suitable treatments for each symptom that occurs.