Ankylosing Spondylitis

What is ankylosing spondylitis?

Ankylosing spondylitis (AS), also known as axial spondyloarthritis, is a chronic inflammatory condition that primarily affects the spine. Over time, inflammation can lead to the fusion of some vertebrae, which are the bones that make up your spine. This fusion can cause stiffness and reduce flexibility, leading to discomfort.

AS typically starts at the sacroiliac joints, where the base of your spine (the sacrum) connects with your pelvis (the ilium). These joints are some of the largest in the body and are essential for movement, especially when shifting or rotating your hips. The inflammation in these joints is often one of the earliest signs of the condition.

While the sacroiliac joints are most affected, ankylosing spondylitis can also impact other areas of the body. Less frequently, AS affects other joints, including:

Shoulders
Hips
Knees

While there is no cure for ankylosing spondylitis, early diagnosis and treatment can help manage the symptoms, slow the progression of the condition and improve the quality of your life.

Ankylosing spondylitis symptoms

Everyone with ankylosing spondylitis experiences different symptoms. The most common symptom is lower back pain caused by sacroiliitis, which is painful inflammation in the sacroiliac joints.

The pain can spread to other areas, including:

Hip pain
Pain in your buttocks
Neck pain
Abdominal pain

Other symptoms of AS may include:

Stiffness or difficulty moving your hips and lower back, especially in the morning or after resting for a long time
Fatigue
Shortness of breath
Loss of appetite or unexplained weight loss
Diarrhea
Skin rashes
Vision problems

When to see a doctor

See a doctor if you have persistent lower back pain, stiffness or discomfort that spreads to your hips, buttocks or neck. Also, get medical advice if you're feeling constantly fatigued, losing weight without explanation or having digestive issues like diarrhea. Early diagnosis and treatment can help manage symptoms and prevent complications.

Ankylosing spondylitis causes

Ankylosing spondylitis is an autoimmune condition. This means your immune system mistakenly attacks your body instead of protecting it.

The exact cause of ankylosing spondylitis isn’t fully understood. However, studies show that certain genetic mutations are strongly linked to the condition. Genetic mutations are changes in your DNA that occur when your cells make copies of themselves.

More than 60 genes may be linked to AS. One example is the human leukocyte antigen-B (HLA-B27) gene. Having a gene known as HLA-B27 increases your risk, but not everyone with this gene develops the condition, which means environmental factors could also play a part.

Ankylosing spondylitis risk factors

While researchers aren’t exactly sure what causes ankylosing spondylitis, certain risk factors can make it more likely to develop. These include:

Age: Symptoms usually start between the ages of 18 and 40.
Family history: If you have family members with ankylosing spondylitis, you may be at a higher risk.
Sex: Ankylosing spondylitis is more common in men than women.
Certain conditions: If you have conditions like Crohn’s disease, ulcerative colitis or psoriasis, you may be more likely to develop ankylosing spondylitis.

Complications of ankylosing spondylitis

In severe cases of ankylosing spondylitis, the body forms new bone as it tries to heal itself. Over time, this new bone can connect the vertebrae in the spine, causing sections of the spine to fuse. This makes the spine stiff and less flexible. The fusion can also affect the rib cage, limiting how much your lungs can expand.

Other possible complications include:

Eye inflammation (uveitis): This is a common issue with ankylosing spondylitis and can cause sudden eye pain, sensitivity to light and blurry vision.
Fractures: Early in the disease, bones can weaken, especially in the spine. This can cause vertebrae to collapse, which can lead to a stooped posture. These fractures may also put pressure on the spinal cord or nerves, which can cause further damage.
Neurological impairment: In the later stages of the condition, when the bones in the spine have fused together, a break in the spine can be very serious. It can snap straight across and damage the nerves, leading to neurological problems like weakness or paralysis.
Heart problems: Ankylosing spondylitis can affect the aorta, the large artery in your body. Inflammation can make the aorta enlarge, which can affect how the aortic valve works. This can increase the risk of heart disease as well.

How is ankylosing spondylitis diagnosed?

Diagnosing ankylosing spondylitis can be difficult. Many of its symptoms are similar to those of other conditions and no definitive test exists for it. Your doctor will do a physical exam and talk to you about your personal and family health history. Imaging tests and blood work can also help your doctor determine the cause of your symptoms and make an accurate diagnosis.

Medical history and exam

Your doctor will review your medical history and ask about your symptoms. They’ll want to know where you feel discomfort, how long it’s been happening and what makes it worse. Your doctor will also ask if anyone in your family has had arthritis or back pain.

During the physical exam, your doctor will focus on your spine and other joints that may be affected, such as your pelvis, chest and heels. You may be asked to bend in different directions and take deep breaths to check for stiffness in your ribs.

Ankylosing spondylitis treatment

Ankylosing spondylitis treatment focuses on managing discomfort, reducing inflammation and helping you keep your mobility and posture. While there’s no cure, effective treatments can make a big difference in your quality of life by controlling symptoms and slowing the condition's progression. Treatment usually includes medications, physical therapy, exercise, and in some cases, surgery.

Physical therapy

Your doctor may suggest physical therapy to help you stay active and follow an exercise program that works for you. Physical therapy can help reduce pain, strengthen muscles (especially those that support your back), improve posture and increase joint flexibility. A physical therapist can also show you sleeping positions that might reduce discomfort from ankylosing spondylitis at night.

The goal of physical therapy is not only to relieve pain but also to help you keep an active lifestyle and prevent further joint damage. It can also teach you how to manage your symptoms in the long run, which is important since ankylosing spondylitis is a chronic condition.

What is ankylosing spondylitis?