Ankylosing spondylitis (AS) is a type of arthritis that can affect many parts of the body. Treatment can help slow the progression of the disease and manage the symptoms.

Ankylosing spondylitis (AS) causes inflammation in the joints of the spine, which can lead to severe, chronic pain. In advanced cases, AS can cause bones in the spine to fuse, leading to a loss of mobility.

Over time, the disease may affect other joints, including the ribs, neck, knees, and feet. In rare cases, people may have heart or lung complications due to AS.

Treatment can slow or halt the progression of the disease, and certain exercises can help people manage their symptoms, relieve pain, and avoid complications.

This article examines how AS affects the body over time, how to treat and manage these effects, and what the outlook is for people with this condition.

In the early stages, AS symptoms often affect only the spine and lower back. In males, AS primarily affects the sacroiliac joint, where the spine and pelvis join. In females, it often first affects the cervical or thoracic spine. The cervical spine consists of seven vertebrae in the neck, and the thoracic spine is the area from the bottom of the neck to the bottom of the ribs.

Over a longer period, stiffness and pain can spread throughout the spine and neck. This spread may occur over several months or years.

AS-related inflammation may also affect organs such as the eyes, heart, and lungs.

According to the Spondylitis Association of America, in its early stages, AS most commonly affects the spine, causing frequent pain and stiffness in the lower back.

The symptoms of AS in the early stages are due to joint inflammation — they are not related to any mechanical cause. They tend to come on gradually over several weeks or months. The symptoms are usually worse in the morning and after rest, but light exercise or a warm shower can often relieve pain and stiffness.

“Ankylosing” means “stiffening,” and “spondylitis” means “spine inflammation.” The combined term “ankylosing spondylitis” refers to spinal stiffness resulting from inflammation and the fusion of bones.

As the inflammation travels up the spine, it can affect a person’s posture. If the spinal bones, called vertebrae, begin to fuse, the person may lose flexibility in their spine. This can result in decreased mobility and changes in posture.

The bones fuse because calcium deposits appear around the ligaments and the disks between the vertebrae. These deposits occur as a result of the bones healing from the inflammation. Spinal fusion leaves the vertebrae brittle and prone to fractures, and it can result in kyphosis, a forward curving of the spine.

Controlling inflammation early — by taking the appropriate medications and doing certain stretches and exercises — can help delay the progression of AS and stop it from spreading farther up the spine or to other parts of the body.

AS primarily affects the sacroiliac joint, but as the disease progresses, it can affect any joint in the body.

Symptoms in all affected joints include pain, stiffness, and swelling.

AS causes inflammation of the synovial membrane, which is the tissue that lines the inside of the joints. This joint inflammation is known as synovitis.

While symptoms of AS can appear in any joint, they are most common in the larger joints of the body.

Symptoms of AS may arise in the joints in the following areas:

  • neck
  • shoulder blades
  • ribs
  • hips
  • knees
  • ankles
  • feet

AS affects the hip and shoulder joints in about one-third of people with the condition.

One hallmark of AS is enthesitis, which is inflammation in the places where ligaments attach to bones. The effects of enthesitis are particularly significant in the feet and can affect mobility. AS mainly affects two areas of the feet: the Achilles tendon and the base of the heel.

In about 15% of people with AS, the inflammation affects the temporomandibular joint, causing jaw pain and difficulty chewing.

Inflammation from AS can spread up the spine and affect the chest because the ribs are attached to the vertebrae. Here, it can cause chest pain and trouble breathing. When inflammation causes stiffness in the ribs, it is more difficult for the chest to expand when a person inhales.

The result is a feeling of air hunger or tightness in the chest. People may feel like their breaths are inadequate as their lungs struggle to expand in a tight rib cage.

If the disease progresses, the ribs may become fused to the spine, worsening these symptoms.

Practicing deep breathing exercises after a shower or using ice packs on the ribs can help. Learning how to do diaphragmatic breathing may also be beneficial.

Inflammation in the eyes, known as iritis or uveitis, is common in AS. About one-third of people with AS have eye inflammation at least once during the course of the disease.

People may experience the following eye-related symptoms:

  • eye pain or pressure
  • increased sensitivity to light, known as photophobia
  • watery, bloodshot eyes
  • dark spots in the vision
  • blurred vision

Many people with AS experience inflammation in the bowel, which is associated with inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis.

As a result of the spinal involvement and subsequent neurological complications, AS can reduce a person’s ability to control urination or bowel movements, leading to incontinence.

Heart and lung complications from AS are rare.

A person may experience an irregular heartbeat or an inflamed aorta, which is the main artery from the heart.

Some people with AS develop sleep apnea, which means that their breathing repeatedly stops during sleep.

In some cases, lung tissue may develop scarring, lesions, or cysts.

Some people may have a functional lung impairment, meaning that it can take longer for respiratory infections and colds to heal.

While there is no cure for AS, various treatments can slow or stop its progression. Treatment plans generally include regular medication and exercises.

Eating a varied and nutritious diet, using hot and cold packs to relieve pain, and avoiding smoking can benefit the overall management of AS and should be part of all treatment plans.


Doctors often recommend nonsteroidal anti-inflammatory drugs (NSAIDs) to manage AS-related inflammation. Pain relievers and local injections of corticosteroids are also options for symptom management.

Doctors may prescribe disease-modifying antirheumatic drugs (DMARDs) in severe AS cases and instances of peripheral disease involvement. These medications can reduce joint inflammation. Examples include:

Most people do not need surgery, but it is an option if the pain is severe or persistent or significantly limits the person’s mobility or quality of life.

Read more about drug treatments for AS here.

Physical therapy

Physical therapy, such as stretching and mobility exercises, can help reduce back pain and stiffness due to AS. Experts recommend doing these exercises every day.

The Spondylitis Association of America recommends that AS exercise programs include the following four elements:

  • Stretching: Range-of-motion stretches can improve flexibility and reduce muscle stiffness, swelling, and pain.
  • Cardiovascular exercise: Aerobic activities such as swimming and walking can help reduce pain and fatigue and improve lung and heart function.
  • Strength exercises: Maintaining strong muscles, especially in the core and back, can improve posture and reduce pain.
  • Balance training: By working on their balance, people can improve their stability and reduce their risk of falls.

Learn about specific exercises for AS and their benefits.

Each person’s experience with AS is unique. The severity and location of the symptoms and the disease progression vary widely among individuals. For example, according to a 2020 research review, men typically have more severe joint inflammation and damage, whereas women typically have higher disease activity and peripheral complications.

AS is a progressive disease. Without treatment, the symptoms may spread and worsen. Many people with untreated AS experience chronic pain and loss of flexibility, and these effects can lead to physical disability.

However, with treatment and lifestyle strategies, people can reach states of remission in which they have less disease activity and fewer physical limitations.

By working directly with a primary care doctor or a rheumatologist, people with AS can usually create a treatment plan that helps them manage AS. Once the plan is in place, following it carefully will help prevent the disease from progressing.

AS is a type of arthritis that primarily affects the spine and lower back. Over time, it can spread to other joints.

The inflammation that AS causes can also affect the organs, including the eyes, the bowel, and — in rare cases — the heart and lungs.

People with AS can prevent disease progression by taking medications as prescribed, doing a range of exercises, and maintaining certain lifestyle habits.