If you’ve received a diagnosis of ankylosing spondylitis (AS), you may be wondering what that means. AS is a type of arthritis that usually affects the spine, causing inflammation of the sacroiliac (SI) joints in the pelvis. These joints connect the sacrum bone in the lower part of the spine to your pelvis.

AS is a chronic disease that can’t yet be cured, but it can be managed with medication and, in rare instances, surgery.

Although AS affects people in different ways, certain symptoms are usually associated with it. These include:

  • pain or stiffness in your lower back and buttocks
  • gradual onset of symptoms, sometimes starting on one side
  • pain that improves with exercise and worsens with rest
  • fatigue and overall discomfort

AS is a chronic, debilitating disease. This means it can get progressively worse. Serious complications can arise over time, especially if the disease is left untreated.

Eye problems

Inflammation of one or both eyes is called iritis or uveitis. The result is usually red, painful, swollen eyes and blurred vision.

About half of patients with AS experience iritis.

Eye issues associated with AS should be treated promptly to prevent further damage.

Neurological symptoms

Neurological problems can develop in people who have had AS for a very long time. This is due to cauda equina syndrome, which is caused by boney overgrowth and scarring of the nerves at the base of the spine.

Though the syndrome is rare, serious complications can arise, including:

  • incontinence
  • sexual problems
  • urine retention
  • severe bilateral buttock/upper-leg pain
  • weakness

Gastrointestinal problems

People with AS can experience inflammation of the gastrointestinal tract and bowels either before the onset of joint symptoms or during the expression of this disease. This can result in stomach pain, diarrhea, and digestive problems.

In some cases, inflammatory bowel disease, ulcerative colitis, or Crohn’s disease may develop.

Fused spine

New bone can form between your vertebrae as the joints become damaged and then heal. This can cause your spine to fuse, making it more difficult to bend and twist. This fusing is called ankylosis.

In people who don’t maintain a neutral (“good”) posture, the fused spine can result in a stooped posture that’s fixed in place. Focused exercise can also help prevent this.

Advances in treatments such as biologics are helping to prevent progression of ankylosis.


People with AS also experience thinning bones, or osteoporosis, especially in those with fused spine issues. This can lead to compression fractures.

About half of AS patients have osteoporosis. This is most common along the spine. In some cases, the spinal cord may become damaged.

Heart and lung problems

Inflammation can sometimes spread to the aorta, the biggest artery in your body. This can prevent the aorta from functioning normally, leading to heart problems.

Heart problems associated with AS include:

  • aortitis (inflammation of the aorta)
  • aortic valve disease
  • cardiomyopathy (disease of the heart muscle)
  • ischemic heart disease (resulting from reduced blood flow and oxygen to the heart muscle)

Scarring or fibrosis in the upper lungs may develop, as well as ventilatory impairment, interstitial lung disease, sleep apnea, or collapsed lungs. Quitting smoking is highly recommended if you are a smoker with AS.

Joint pain and damage

According to the Spondylitis Association of America, about 15 percent of people with AS experience jaw inflammation.

Inflammation in the areas where your jawbones meet can cause serious pain and difficulty opening and closing your mouth. This could lead to problems with eating and drinking.

Inflammation where ligaments or tendons attach to the bone is also common in AS. This type of inflammation can occur in the back, pelvic bones, chest, and especially the heel.

Inflammation may spread to the joints and cartilage in your ribcage. Over time, the bones in your ribcage may fuse, making chest expansion difficult or breathing painful.

Other affected areas include:

  • chest pain that mimics angina (heart attack) or pleurisy (pain when breathing deeply)
  • hip and shoulder pain


Many AS patients experience fatigue which is more than just being tired. It often includes a lack of energy, severe tiredness, or brain fog.

Fatigue related to AS can be caused by a number of factors:

  • loss of sleep from pain or discomfort
  • anemia
  • muscle weakness making your body work harder to move around
  • depression, other mental health issues, and neurological changes
  • certain drugs used to treat arthritis

Your doctor may suggest more than one type of treatment to address issues of fatigue.

If you are experiencing back pain, it’s important to see a healthcare provider as soon as you can. Early treatment is beneficial for reducing symptoms and slowing progression of the disease.

AS can be diagnosed with an X-ray and MRI scan showing evidence of inflammation and a lab test for a genetic marker called HLA B27. Indicators of AS include inflammation of the SI joint at the lowest part of the back and the ilium on the upper part of the hip.

AS risk factors include:

  • Age: Typical onset is late adolescence or early adulthood.
  • Genetics: Most people with AS have the HLA-B27 gene. This gene doesn’t guarantee you’ll get AS, but it can help diagnose it.