• In severe AS, spinal fusion can occur and other body parts can be affected.
  • Therapies and medications can help you manage symptoms.
  • Treatments to reduce your immune response can help prevent further damage.

Ankylosing spondylitis (AS) is a progressive, inflammatory form of arthritis that affects the spine and other joints. Not everyone with AS will experience the exact same symptoms or have identical joint pain. Progression of the condition varies from person to person, too.

Some people have mild cases that are relatively easy to manage. Other people, with more severe cases of arthritic inflammation, may experience complications.

In severe or late stage AS, pain and inflammation can cause serious damage in your body. People with AS often feel this in the spine first, where pain and stiffness worsen as the spine becomes less flexible.

It can take an average of 4 to 9 years to get a proper diagnosis and start treatment for AS, according to a 2006 research review.

Sometimes, there’s already joint damage by the time a diagnosis is made. In late stage AS, ongoing inflammation in the spine can cause joints to fuse together.

Healthcare professionals can see structural damage from ongoing inflammation in X-rays, according to 2018 research. They often use these images to make a diagnosis.

At this stage, other parts of the body may also have damage. Even with severe AS, though, treatment can help control your symptoms and prevent further progression of the condition.

Keep reading to learn more about how you can manage severe AS and its complications.

In severe AS, inflammation affects your whole body. Over time, damage from this inflammation causes the vertebrae in the spine to fuse. This causes back pain to worsen and impacts mobility and flexibility.

Some of the signs and symptoms of severe AS include:

  • persistent back pain, especially in the lower back
  • loss of flexibility and movement in the spine
  • changes in the structure of the spine, seen in X-rays
  • spinal fractures, also seen in X-rays
  • feelings of chest tightness

Not all people with severe AS will experience every possible complication. Complications directly related to the spine are most likely to occur.

The immune response that targets the spine in AS can also harm other parts of the body. Some people with AS have symptoms that affect their lungs, heart, eyes, and digestive system.

Bamboo spine

Your spine is made up of several bones called vertebrae. Normally the vertebrae can support a wide range of movement.

In severe AS, the joints connecting the vertebrae are damaged. As they try to heal from the inflammation, extra bone starts to grow. This extra bone causes the vertebrae to fuse together.

When this happens, it greatly impacts your spine. It can no longer move, bend, and twist as it typically does.

X-rays show that a spine damaged by AS looks like a stalk of bamboo, according to 2019 research, which is where the term “bamboo spine” comes from.

You can do physical therapy and take anti-inflammatory medications to help manage bamboo spine.

Increase in pain

People with AS will experience different levels of pain. In severe AS, when the spine is no longer flexible, pain tends to be greater.

This is because your spine can’t support the rest of the body as it typically would, which puts greater pressure on other joints. People with bamboo spine may feel more pain in their shoulders and hips as their body tries to adjust for spinal changes.


Osteoporosis is when bones become weak and more likely to break.

People with severe AS have greater chances of also having osteoporosis. The extra bone that grows and fuses the spine makes the spine brittle, with greater chance of breakage.

If you have AS, you should be screened for osteoporosis within 10 years of diagnosis. Your doctor may recommend several strategies to improve bone health, such as:

  • dietary changes
  • supplements
  • exercise

They may also suggest medications that work to reduce further bone loss.

Lung complications

When the spine fuses together, it can affect breathing and lung function. The chest wall becomes more rigid, making it harder to take deep breaths. This causes chest pain and tightness.

Bamboo spine can also increase the risk of lung complications, according to a 2013 case study. These may include:

  • lung infection
  • spontaneous pneumothorax, when air escapes from a lung, causing it to collapse
  • pulmonary fibrosis, when tissue in the lung becomes damaged and scar tissue builds up, making it more difficult to breathe

In general, your risk for lung complications are likely to increase the longer you’ve had AS.

Heart disease

Heart disease is a general term for any condition that affects your heart or blood vessels. People with AS, especially severe AS, are at a higher risk of developing heart disease than those without the condition.

However, you can do many things to keep your heart healthy:

  • Eat a variety of fruits and vegetables.
  • Aim for 7 to 8 hours of sleep each night.
  • Keep your stress levels down.
  • Try to stay active.
  • Maintain a healthy weight.
  • Know your cholesterol, blood pressure, and blood sugar levels — when high, these increase your risk of heart disease.

One review from 2016 explored how AS and different types of heart disease might be connected. Researchers found that aortic insufficiency and conduction disorders were most common in people with AS.

Cauda equina syndrome

This rare condition is considered a medical emergency. Intense pressure and swelling of the lower spinal cord nerves can lead to weakness, tingling, or numbness in the legs or feet. Often, bowel or bladder dysfunction also occurs.


This is an extremely rare condition, in which one or more intervertebral discs or disc spaces become inflamed. It’s most commonly due to infection.

A hunched posture

If the spine fuses together in a certain way, it can result in a permanent change in the spine’s shape.

This type of spine fusion causes a person to hunch forward. Over time, the chin-to-chest posture may impact a person’s organs, including the heart and lungs.

If you have AS, several treatments can help you manage your condition and improve your quality of life.

It’s likely that your treatment plan will change over time. Having regular check-ins with your doctor gives you a chance to discuss any notable changes in your health.

If you begin to experience new symptoms, your doctor can work with you to adjust your treatment plan before symptoms progress further.

Treatment goals for severe AS include:

  • managing daily symptoms
  • improving mobility and quality of life
  • preventing further progression of AS

Here are the main treatments used as part of severe AS management:

  • Physical therapy. Working with a physical or occupational therapist can be really helpful. These professionals can support you in finding ways to stay mobile and strong when your spinal movement is limited.
  • Heat therapy. Using a heating pad can help ease sore, tight muscles. Keep in mind that heat is not recommended for use on inflamed joints since it can increase blood flow and swelling.
  • Cold therapy. Using a cooling pack or ice wrapped in a towel can help to reduce joint swelling. Don’t apply ice directly to your skin, though. Instead, use a bag or wrap a towel around the ice.
  • Nonsteroidal anti-inflammatory drugs (NSAIDS). These are often a first-line treatment to help manage inflammation and pain, but they don’t prevent further damage. Many NSAIDS don’t require a prescription.
  • Corticosteroids. These medications, taken orally or by injection, are powerful anti-inflammatories that can start working within hours or days. Due to side effects, though, they aren’t typically used long-term.
  • Disease-modifying antirheumatic drugs (DMARDs). These are usually taken orally, though one type, Methotrexate, can be injected. DMARDs lessen disease activity and can prevent further damage to joints. They may be used in AS but are more likely to be used for other types of arthritis, according to the Spondylitis Association of America.
  • Biologic medications. Two groups of biologics are used for AS: TNF inhibitors and IL-17 inhibitors. They block specific immune proteins that trigger inflammation and pain. They also prevent further damage from inflammation.

Even with severe AS and resulting complications, you can find ways to decrease the discomfort and prevent further damage.

Medications can help you manage daily symptoms and reduce the immune response. Often, a combination of medications and therapies works best.

A rheumatologist will likely monitor your condition, though other specialists may get involved as needed. Be patient, communicate, and ask questions. The doctors and nurses are there to help you.

AS is an inflammatory disease that mainly targets the spine. Severe AS causes damage to the spine, making it rigid and inflexible.

A variety of treatment options are available for AS and its complications. Several medications are used to manage daily symptoms while also preventing further damage to the spine and other parts of the body.