Ankylosing spondylitis (AS) is a type of arthritis, so it’s not surprising that its main symptoms are pain and stiffness. Since the disease inflames joints in the spine, pain is usually centered in the lower back.

But ankylosing spondylitis isn’t just confined to the spine. It can affect other parts of the body as well, causing some surprising symptoms.

We’ll overview what AS is and 10 ways it can affect your body that you might not expect.

AS is considered both an autoimmune type of arthritis and an inflammatory condition. This means your immune system attacks your joints and where tendons and ligaments attach to bone.

Ankylosing spondylitis often occurs in flares, or periods when the inflammation is worse than usual.

The onset of AS typically occurs before the age of 40, and your biological sex can affect your risk. Research that grouped participants into categories of women and men indicates that men are more likely to develop the condition than women.

However, women can still have AS. The diagnosis is often missed because it tends to present in their thoracic spine, the upper-middle part of the back. AS is usually associated with pain in the lower back and sacroiliac joint, where the pelvis and spine meet.

In severe cases, AS can cause the vertebrae in your spine to fuse (ankylosis), leading to stiffness and immobility. This extreme outcome is sometimes referred to as bamboo spine. Most cases of AS do not progress to this stage, and biologic medications can help lessen the risk.

The hallmark joint-related symptoms of AS include:

  • pain in the sacroiliac joint in almost all cases
  • chronic lower back pain
  • stiffness in your spine
  • buttock soreness
  • pain in the hips, knees, or fingers in some cases

Factors used to help identify AS include:

Usually, a doctor will only diagnose AS if inflammation is present on your X-ray. However, this can take 7 or more years after symptoms first appear.

If you present similar symptoms but your inflammation can’t be seen on an X-ray, you may be experiencing a different type of spondyloarthritis.

AS and the (HLA)-B27 marker

Ankylosing Spondylitis is closely tied to a specific human leukocyte antigen called (HLA)-B27, a protein found on white blood cells.

This marker is found in around 90 percent of people with AS. It can be identified with a routine blood test. Rheumatologists will test for this marker when evaluating you for AS or other conditions.

However, the majority of people who have (HLA)-B27 will never develop AS. It is also possible to have AS without the marker.

Treatment for AS may include any combination of the following:

Treatment may vary widely depending on your specific symptoms and the severity of your AS. Consult with your doctor before pursuing any at-home therapies, such as massage, heating, or icing.

Let’s jump into the unique ways AS can affect your body outside the spine and sacroiliac joint.

Chest pain with AS often stems from inflammation in the ribs, spine, and sternum. The scarring and stiffening of these areas make it hard to expand your chest and lungs fully enough to get a deep breath. When doing so, your chest may feel very tight and sore.

Areas where ligaments and tendons attach to bone can also become inflamed when you have AS. This symptom is called enthesitis. It creates “hot spots” for pain in areas like the chest, pelvis, and heels.

Research from 2016 has associated ankylosing spondylitis with heart problems, especially in older adults. This can contribute to chest pain and affect your life expectancy if not addressed.

Heart conditions observed in those with long-term AS include:

Heart complications in AS should be taken seriously. Your doctor may order blood tests and imaging in order to develop the best treatment plan for you.

Treatment for cardiac problems varies.

It can look like:

  • developing an exercise routine
  • making diet and lifestyle changes
  • taking medication
  • having surgery, in severe cases

AS chest pain can feel like angina, which is when too little blood flow is getting to your heart. Because angina is an early warning sign of a heart attack, contact your doctor right away if you think you may be experiencing it.

Chest pain is also common in other noncardiac health conditions, including acid reflux, viral infections, and broken ribs.

If you or a loved one are experiencing the possible symptoms of a heart attack, seek emergency assistance immediately.

AS also causes inflammation and scarring in the lungs themselves, called pulmonary fibrosis. Combined with the chest tightness, you may develop diminished lung capacity. This can feel like chronic shortness of breath or coughing, especially when you exercise.

Issues with chest soreness and lung expansion due to AS can be addressed in several ways:

It can be hard to tell breathing issues caused by AS from those of another lung condition. Talk with a doctor if you’re experiencing any difficulty or discomfort when breathing.

According to a 2016 study, between 30 and 40 percent of people with AS develop an eye complication called iritis, or acute anterior uveitis (AAU), at least once. Iritis occurs when the front part of the eye becomes red and inflamed.

This redness in your eye may be accompanied by:

  • pain
  • light sensitivity
  • blurred vision

Sometimes iritis will only occur once, but for others, it may be a chronic (long-term) issue.

See an eye doctor as soon as possible if you have these symptoms. Iritis is very treatable, often with prescription steroid eye drops. If the condition goes untreated, you could have permanent vision damage or loss.

Fever is a common early symptom in people with spondyloarthritis, including ankylosing spondylitis.

Several early symptoms of AS sometimes seem more like the flu, rather than signs of arthritis. Along with a low fever, some people lose their appetite or feel generally unwell. These unclear symptoms can make the disease harder for doctors to diagnose.

Night sweats are also reported by some people with AS. They can disrupt sleep and should be monitored by you and your doctor.

When your immune system launches an attack against your own body, it releases inflammatory substances called cytokines. Too much of these chemicals circulating in your body can make you feel tired.

Inflammation from AS can also exhaust you. It takes a lot of physical and emotional energy for your body to control it while managing your daily life.

AS can also cause anemia — a drop in red blood cells. These cells carry oxygen to your body’s organs and tissues. When your body doesn’t get enough oxygen, you’ll feel tired.

Ankylosing spondylitis and depression

Fatigue is also a symptom of depression, which is a common comorbidity (coexisting condition) in those living with chronic pain, such as that caused by AS.

People with AS have been found to have a higher prevalence of depression than the general population:

  • A 2019 study from South Korea found that people with AS had more than twice the risk of depression than those without the disease.
  • Another 2019 study reported people with AS were more likely to be depressed when they felt less control over their life and disease progression.

Getting the right mental health care and support can be an essential part of living with ankylosing spondylitis.

If you or someone you know is considering suicide, seek help from emergency services, or from a crisis or suicide prevention hotline. You’re not alone — support is available. The National Suicide Prevention Lifeline can be reached at 800-273-8255.

Fatigue from AS can also stem from another common symptom — difficulty falling and staying asleep.

One of the hallmarks of AS is that pain often worsens with rest and improves with movement. This can make nighttime particularly unpleasant, as pain and inflammation interfere with sleep.

According to a 2017 research review, 35 to 90 percent of those with AS reported disturbed sleep. Insufficient sleep, in turn, negatively affects mood and energy, which can create an exhausting cycle.

Here are some tips on how to get enough rest, even with chronic pain:

In people with AS, a common site of enthesitis is the Achilles tendon at the back of the heel and the plantar fascia at the base of the heel.

After the chest, the Achilles is the second most common site of enthesitis in people with AS. Pain in one or both feet due to AS can make it difficult to walk or stand, and it can keep you up at night.

Ways AS can affect your feet include:

  • soreness
  • stiffness
  • limited range of motion
  • swelling

While AS heel changes may not show up on X-rays, MRI scans can show them, even early in disease progression.

It’s important to listen to your body and respect your limitations. Wearing comfortable shoes with good arch support may help prevent pain from worsening. Pain medications and physical therapy can also help with symptoms.

People with ankylosing spondylitis are more likely to have inflammation of the jaw compared with the general population.

Jaw swelling and inflammation is called temporomandibular joint (TMJ) disorder. Pain and swelling in your jaw can make it hard to eat or talk, and it may keep you awake at night.

Treatment often involves at-home remedies, such as:

Many people with AS report digestive issues, including abdominal pain and diarrhea. A 2015 study of 113 patients with AS found 30 percent had irritable bowel syndrome (IBS).

Ankylosing spondylitis is in a family of diseases called the spondyloarthropathies, which includes inflammatory bowel disease (IBD). According to older 2006 research, approximately 5 to 10 percent of those with AS had a form of IBD as well.

Trouble controlling your bladder and bowels isn‘t a common symptom of AS, but it can occur for some in late stages of the disease.

In these rare instances, scars form on the nerves at the base of the spine. This complication is called cauda equina syndrome (CES). Pressure on the nerves in your lower spine make it hard to control urination or bowel movements. Other symptoms of CES include leg weakness and numbness.

Appetite loss is one of the early signs of AS. It often goes along with general symptoms like fever, fatigue, and weight loss early in the disease onset.

The ambiguous, flu-like symptoms of AS can be exhausting and affect your entire well-being. It’s important you communicate with your doctor to make sure you receive the care you need and deserve.

Appetite loss can also be a symptom of many other health conditions, including viral or bacterial infections.

The main symptoms of AS are pain and stiffness in your lower back, buttocks, and hips. It is possible to have other symptoms across the body. These include eye inflammation, chest pain, and irritated bowels.

Medications like NSAIDs and biologics can help bring down system-wide inflammation. Diet and lifestyle changes as well as other treatment methods like physical therapy or massage can help relieve pain and improve mobility.

No matter what symptoms you have, it’s important to see a doctor for evaluation. While AS currently has no cure, many of its symptoms are very treatable. With proper care and support, it’s possible to manage your AS and live a healthy, fulfilling life.