​Ankylosing spondylitis (AS) is a chronic, progressive form of inflammatory arthritis. In AS, the immune system mistakenly attacks the spine and sacroiliac joints (the joints connecting the lower spine to the pelvis), leading to pain and joint damage. The condition is also referred to as radiographic axial spondyloarthritis (r-axSpA), meaning the damage can be seen on X-rays.

As with other types of inflammatory arthritis, such as rheumatoid arthritis, early diagnosis and treatment for AS are crucial to managing symptoms and slowing disease progression. This approach can help prevent joint deformity, excess bone formation in the spine, disability, and associated health problems. Once damage caused by AS develops, it’s irreversible (permanent).

Continue reading to learn more about the progression of AS and how it affects the body.

How Fast Does Ankylosing Spondylitis Progress?

The progression of AS can vary widely from person to person. Some researchers have found that AS worsens by about 35 percent for each 10-year period. However, symptoms and severity of the disease can change over time. Many people with the condition notice lower back pain early on, whereas others might first notice pain in areas like the hips or knees.

If left untreated, AS can lead to the formation of new bone in the spine, which may cause painful ankylosis (spinal fusion). This process can result in a condition known as “bamboo spine,” where the fused vertebrae (the small bones in the spine) take on the appearance of a bamboo stalk in X-rays. However, not everyone with AS will develop this complication.

In addition to the spine, AS may affect other joints, such as the neck, shoulders, jaw, hips, hands, feet, fingers, and toes. Because AS involves chronic inflammation throughout the body, some people may also experience complications beyond the joints. These include eye problems, heart issues, fatigue, and nerve damage.

Early-Stage Ankylosing Spondylitis

AS is considered to be early-stage if an individual has had symptoms for two years or less and the condition has not progressed beyond the initial symptoms of ankylosing spondylitis discussed below.

Back Pain

For most people with AS, lower back pain is the first noticeable symptom. The disease typically starts at the sacroiliac joints, where the lower spine connects to the pelvis. Pain can also be felt on one side or both sides of the lower back early on. It may also occur in other areas of the back, including the neck or buttocks.

In the early stages of ankylosing spondylitis, back pain often develops gradually over weeks or months. Unlike mechanical back pain, which can result from lifting something heavy, AS pain is inflammatory in nature. This means it lingers, can worsen over time, and may feel more intense in the morning or after long periods of inactivity. Movement and anti-inflammatory medications usually help relieve the pain.

Stiffness

AS primarily affects the joints in the spine. When the joints don’t move for a period of time, they become stiff. For example, people with AS often experience stiffness in the morning that can last one to two hours. Chronic inflammation adds to this stiffness, making it painful to move after being inactive, such as when getting up in the morning.

Fatigue

Fatigue is another early sign of AS, although it tends to become more significant as the disease progresses. Because AS is an inflammatory condition, the body works harder than normal to fight ongoing inflammation, leaving you feeling drained of energy.

One MySpondylitisTeam member shared, “I can muscle through pain, but it’s very hard to function when you feel like the plug on the drain has been pulled and you are sitting on empty.”

Later-Stage Ankylosing Spondylitis

While the spine is often the primary source of pain in AS, other joints can become involved as the disease progresses. Tissues like muscles and tendons may also be affected. In addition, complications can arise in other organs, such as the eyes and heart.

Painful Joints

When AS progresses, additional joints may become inflamed and painful. Inflammation can also affect the ligaments and tendons surrounding these joints. One commonly affected area is the entheses, the site where tendons and ligaments attach to bone. Inflammation of the entheses, known as enthesitis, is a hallmark of AS. The Achilles tendon, located at the back of the heels, is frequently involved, causing intense pain, swelling, and difficulty walking. Besides the back and heel, commonly affected areas include the hips, shoulders, knees, and ribs.

“My body feels broken, bruised, beaten, and wrapped in barbed wire all the time,” a MySpondylitisTeam member wrote.

Eye Inflammation

About half of people with spondylitis eventually develop painful, red eye inflammation caused by iritis or uveitis (inflammation of the iris or other parts of the eye). This can lead to blurred vision and photosensitivity (sensitivity to light). If left untreated, eye inflammation can result in vision damage or even blindness. Treatment typically begins with topical corticosteroids to reduce inflammation.

Read more about spondylitis eye inflammation.

Heart Complications

Between 2 percent and 10 percent of people with AS will develop cardiovascular problems associated with the disease. These complications may include:

• Coronary artery disease
• Abnormal heart rhythm
• Inflammation of the aorta, the large blood vessel that carries blood from the heart to other parts of the body
• Heart valve diseases
• Problems with the heart muscle that that impair its ability to pump blood effectively

Read more about how AS affects the heart.

Gastrointestinal Problems

The inflammation associated with AS may cause gastrointestinal issues, such as diarrhea. In some cases, it may be linked to inflammatory bowel disease (IBD), such as Crohn’s disease or ulcerative colitis. Studies have found that between 4 percent and 14 percent of people with spondyloarthritis develop IBD.

Brain Fog

Some studies suggest that AS may increase the risk for cognitive problems, including difficulties with brain functions such as thinking, remembering words, and concentrating. MySpondylitisTeam members have also reported these types of issues. “I’m amazed at how many other people are going through this, too,” one member shared. “I started mixing up words right after my neck surgery. It gets so frustrating. My kids made fun of me, not realizing how much it bothered me.”

Health experts believe the inflammation associated with AS may contribute to cognitive difficulties by affecting in the same way it damages joints, heart, and other parts of the body. Additionally, AS can disturb sleep and interfere with physical and social activities, all of which can also impact cognitive function.

Advanced-Stage Ankylosing Spondylitis

In advanced cases of AS, new bone formation in the spine can cause spinal fusion. This process, known as ankylosis, gives AS its name. Spinal fusion leads to immobility, kyphosis (forward rounding of the spine), and an increased risk of fractures (breaks) in the vertebrae.

Kyphosis causes a bent-forward posture, even when attempting to stand straight. Additionally, spinal fusion can limit the rib cage’s ability to expand, which may lead to trouble breathing. In rare cases, AS may result in neurological complications such as cauda equina syndrome, a condition where the nerves at the end of the spinal cord become compressed. This can lead to pain, numbness, weakness in the legs, and — in severe cases — loss of bladder or bowel control.

Ankylosing Spondylitis Life Expectancy

While people diagnosed with AS generally have a normal life expectancy, certain complications of the disease can potentially shorten lifespan, especially as the condition progresses. If you have any questions or concerns about how AS may impact your health, talk to your health care provider to get the information and support you need.

Treatment for Preventing Progression of Ankylosing Spondylitis

Although there’s currently no cure for AS, many treatment options are available to manage symptoms and prevent disease progression. Without treatment, AS can worsen over time, significantly reducing independence and quality of life.​​

AS treatments include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil or Motrin) — These help control pain and inflammation.
• Traditional disease-modifying antirheumatic drugs (DMARDs) — These are used when joints besides the spine are affected, as they are not effective for spinal inflammation.
• Biologics, such as tumor necrosis factor-alpha (TNF-alpha) inhibitors and interleukin inhibitors — These drugs can help slow disease progression.
• Janus kinase (JAK) inhibitors — A newer class of medications, JAK inhibitors can also help manage symptoms of ankylosing spondylitis.
• Physical therapy — Working with a physical therapist is helpful for maintaining flexibility, mobility, and overall function.

The treatment your rheumatologist or other health care provider recommends will depend on various factors, including the severity of your symptoms, how much the disease has progressed, and whether other joints or organs are affected. Treatments are often combined to manage different aspects of the disease, and biologics may be added when NSAIDs alone are not sufficient. Your treatment plan should also reflect your personal preferences and goals, such as maintaining physical activity or managing side effects.

It’s important to attend all follow-up appointments so your rheumatology team can monitor your condition and adjust your treatment plan as needed. Work closely with your health care providers to find an effective treatment plan you can stick to. Additionally, lifestyle changes, such as quitting smoking, getting regular exercise, and following an anti-inflammatory diet, may further help improve symptoms and overall health.

Read more about advanced treatments for ankylosing spondylitis.

Talk With Others Who Understand

MySpondylitisTeam is the social network for people with spondylitis and their loved ones. On MySpondylitisTeam, more than 98,000 members come together to ask questions, give advice, and share their stories with others who understand life with spondylitis.

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