Ankylosing spondylitis
Find a doctorAnkylosing spondylitis (AS) is a type of arthritis that primarily affects the spine and sacroiliac joint, causing inflammation, pain and stiffness. This chronic illness, often beginning in young adults, can lead to more severe complications if left untreated.
Recognizing the symptoms and seeking timely treatment can make a significant difference in managing this condition. Our team of rheumatologists will help you understand ankylosing spondylitis and develop a treatment plan designed specifically for you.
What is ankylosing spondylitis?

As it progresses, ankylosing spondylitis causes inflammation in the spine leading to the fusion of vertebrae.
Ankylosing spondylitis is a form of arthritis that primarily affects the spine, specifically the sacroiliac joints located between your pelvis and lower back. Over time, this inflammation can lead to ankylosis, a condition where the bones in your spine fuse together. This fusion creates something known as a bamboo spine – due to bamboo-like characteristics such as being stiff and less flexible – which severely limits flexibility and mobility.
While the sacroiliac joints are the most commonly affected, ankylosing spondylitis can also affect other large joints, including the hips and shoulders, and even the eyes, leading to redness and swelling. This condition is more common in people assigned male at birth.
What can cause ankylosing spondylitis?
The exact cause of ankylosing spondylitis remains unclear, but a combination of genetic and environmental factors is believed to play a role. The presence of the HLA-B27 gene is a significant risk factor, though not everyone with this gene develops ankylosing spondylitis. Genetic testing can help determine if the HLA-B27 gene is present.
Spinal infections that activate the immune system, leading to inflammation in the sacroiliac joints and spine can also play a role.
Chronic stress, physical trauma or prolonged exposure to cold weather can make symptoms worse. While these can lead to the development and progression of ankylosing spondylitis, they don't directly cause the disease.
What is the HLA-B27 gene?
The HLA-B27 gene is found in about 90% of people with ankylosing spondylitis, although it's important to note that not everyone with the HLA-B27 gene will develop ankylosing spondylitis.
This gene produces a protein that helps the immune system tell the difference between the body's cells and harmful bacteria and viruses. However, in people with ankylosing spondylitis, this gene may cause the immune system to mistake the sacroiliac joints and spine as something dangerous.
Ankylosing spondylitis symptoms
Symptoms of ankylosing spondylitis often start gradually with dull pain and stiffness in the lower back and sacroiliac joints. These symptoms are typically worse in the morning or after periods of inactivity and may improve with exercise. However, as the disease progresses, the pain can become more persistent and severe.
Common signs of ankylosing spondylitis include:
- Chest pain
- Fatigue
- Lower back pain and stiffness, especially in the sacroiliac joints, pelvis and hips
- Pain and swelling in large joints, such as the shoulders and hips
- Redness and pain in the eyes, which can cause sensitivity to light and blurred vision
- Restricted movement
If you experience these symptoms, especially if you're a young adult, schedule an appointment with your doctor to discuss your symptoms.
Complications of ankylosing spondylitis
If left untreated, ankylosing spondylitis can lead to severe complications, including:
- Bamboo spine: Vertebrae fuse together and cause the spine to become rigid.
- Heart problems: Inflammation can spread to the heart and aorta artery, increasing the risk of cardiovascular disease.
- Breathing difficulties: Fusion of the ribs can restrict chest expansion, making it difficult to breathe.
- Eye inflammation: Frequent episodes of redness and swelling in your eyes can result in potential vision loss.
Living with a chronic illness such as ankylosing spondylitis can also take a toll on your mental health, leading to anxiety and depression. Addressing these complications early with a comprehensive treatment can help you manage this disease.
Diagnosing ankylosing spondylitis
For an ankylosing spondylitis diagnosis, your doctor will begin by reviewing your medical history and performing a physical exam. During the exam, they’ll check your spine and sacroiliac joints for pain, swelling and stiffness.
Blood tests can also help diagnose ankylosing spondylitis, especially if the HLA-B27 gene is present. While the presence of this gene is not necessary for an ankylosing spondylitis diagnosis, it can be a good indicator, particularly when combined with other symptoms.
Imaging tests like X-rays, an MRI or CT scans are crucial in detecting changes in the sacroiliac joints and spine. These images can reveal early signs of ankylosis or other structural changes.
Ankylosing spondylitis treatment
Treatment for ankylosing spondylitis focuses on reducing pain, managing symptoms and slowing the progression of the disease. While there's no cure for ankylosing spondylitis, many treatments can help effectively manage this disease.
Medication for ankylosing spondylitis
Nonsteroidal anti-inflammatory drugs (NSAIDs) are often the first line of treatment to help manage pain and inflammation. These medications can be effective, particularly in the early stages of the disease. If you don't respond to NSAIDs, other medications, including antirheumatic drugs (DMARDs) may be recommended.
Therapy for ankylosing spondylitis
Physical therapy plays a vital role in treating ankylosing spondylitis. A physical therapist can design a personalized exercise program to help you improve posture, increase flexibility and strengthen the muscles around your spine and sacroiliac joints.
Regular exercise and maintaining a healthy weight can reduce stress on your joints and help you improve your overall health.
Surgery for ankylosing spondylitis
In severe cases where there is significant joint damage or when ankylosis spondylitis severely limits mobility, surgery may be necessary. Joint replacement or corrective spinal surgery can reduce pain and restore function. Most people with ankylosis spondylitis won’t need surgery, and it’s usually considered only after other treatments have been exhausted.
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