Ankylosing spondylitis (AS) is more than painful. It can be debilitating.
AS is an inflammatory, autoimmune condition that typically begins in young adulthood, but often gets overlooked, or incorrectly diagnosed as pain from a previous injury or aging. It’s an underdiagnosed form of arthritis that creates inflammation in the spinal joints and causes chronic back pain and stiffness.
AS is progressive. People may begin feeling pain in the lower back or buttocks region, and it can migrate to other areas of the body like the hips, neck, or shoulders. For some, if left untreated, the inflammation caused by AS may cause your spine to fuse, resulting in what some people have referred to as "bamboo spine."
refers to abnormal stiffening and immobility of a joint because of fused bones.
is defined as inflammation of the spine.
AS is difficult to diagnose
Average number of years from onset of symptoms to diagnosis
Average age at diagnosis
Estimated number of people in the United States with AS and related conditions
What are the symptoms of AS?
Signs and symptoms of AS will commonly develop along the spine, but may progress over the course of the disease. People with AS often experience spinal stiffness and loss of spinal mobility due to inflammation.
To better understand inflammation and AS symptoms, and the role the immune system plays in both, we’ve enlisted Dr. Elizabeth Perkins, a practicing rheumatologist, for help.
“It really starts with how we look at the immune system. You basically have different cytokines circulating throughout the body. But in autoimmune diseases, those cytokines can be out of balance.
In our healthy state, that balance is nice and orchestrated—think of it like musical instruments. Everything sounds just right. But in states like AS, some of those cytokines get turned on and overproduce. They get very noisy. And that overproduction of cytokines causes inflammation that can be felt as lower back pain and stiffness.”
—Dr. Elizabeth Perkins, a Practicing Rheumatologist
Chronic pain and stiffness
An overall sense of discomfort that may come and go but never really goes away (chronic).
“With AS, you’re always stiff. You can’t really move.”
Pain and stiffness in the lower back and buttocks
Inflammation of the sacroiliac (SI) joints that results in pain where the spinal joints meet the pelvis.
“Pain started in my lower back and it was chronic, it never stopped.”
Inflammation, dull pain, and stiffness, often worse in the morning
May affect the shoulders, hips, ribs, knees, heels, and neck.
“Waking up with stiff joints and lower back pain—it’s the first thing I feel when I open my eyes.”
What’s the difference between mechanical and inflammatory back pain?
Mechanical back pain
This is a common form of back pain, and may be caused by an injury or overuse. It usually goes away after 6 weeks.
Inflammatory back pain
This is usually caused by certain diseases and begins to appear in people under the age of 35. The symptoms may last 3 months or longer and tend to come and go but never really improve. Inflammatory back pain is a chronic condition, which means that it never really goes away. The pain and stiffness often come back.
AS affects men and women differently
Compared with men, women with AS typically:
- Are younger at onset
- Are diagnosed later
- Have more neck and peripheral joint pain, which is pain in the joints further away from the spine (like in the knees, elbows, and ankles), and could have less spinal involvement.
"I just started noticing a lot of joint pain that didn't really seem to make sense. At first I thought I had overdone it at the gym."
Who’s at risk of developing AS?
There is a potential genetic link.
This is a gene that has been associated with AS.