Ankylosing spondylitis (AS) is a form of arthritis. AS can vary a lot from person to person.
AS is a chronic inflammatory disease. If you have this condition, it affects your spine and joints, causing pain and limiting your range of motion.
AS can involve disease flare-ups that cause acute symptoms, followed by remissions in which symptoms ease.
The most common symptoms of AS include:
- pain in the spine, lower back, neck, and hips
- pain in ankles and knees
- stiffness after rest or sleep
- fatigue
- anemia
- systemic issues, like inflammatory bowel disease and psoriasis
A 2019 study suggests women might be more likely to report digestive symptoms and skin involvement, and men might have more eye symptoms.
According to a
Overall, there is not a clearly identified and consistent difference when it comes to symptoms between women and men.
Language matters
Sex and gender exist on a spectrum. We use “women” and “men” in this article to reflect the terms assigned at birth. However, gender is solely about how you identify yourself, independent of your physical body.
AS is rare. In the United States, about
For decades, doctors believed men were significantly more likely to develop AS, but as research has improved, that image has changed dramatically. At one point, men held a
What’s more, women are more likely to be underdiagnosed and wait longer for a diagnosis. That’s why researchers believe the real prevalence among women may not be fully understood yet.
On average, it takes longer for women to receive an AS diagnosis than it does for men: Women wait about 8.8 years for a diagnosis, while men wait 6.5 years, according to a 2017 study.
A rheumatologist usually makes the diagnosis of AS. There’s no single test for AS, so reaching that diagnosis may include:
- individual and family medical history
- evaluation of symptoms
- physical examination
- imaging tests
- blood work
Imaging tests, like X-rays, are highly valuable for diagnosing AS. That’s because the disease can cause damage to the sacroiliac joint (the joint that connects the hips to the sacrum). This damage is visible on X-rays.
However, some people with the condition will not show obvious signs of damage. This type of AS is called non-radiographic axial spondylarthritis (nr-AxSpA). It’s more common in women than men.
The assumption that AS is a predominantly male condition may also delay diagnosis in women.
In addition, studies have generally included many more men than women. Newer studies are addressing this. But much more research is necessary to broaden the understanding of any gender differences, including differences in symptoms, hereditary factors, and what the best treatments are.
AS develops from a specific pattern of inflammation affecting the spinal vertebral bodies and the ligaments and tendons that attach to these bones of the spine. Over time, this swelling causes severe problems within the back.
At first, you may experience frequent back pain or overall stiffness, which may be worse in the morning or after long periods of sitting. You might notice that it improves a bit after a warm shower or a little exercise.
Several factors may cause women to have a higher disease burden: delay in diagnosis, higher disease activity, and less responsiveness to standard treatment.
A 2018 review found that women have higher disease activity and may have more damage that is not visualized on standard imaging tests. Women are also less responsive to some of the primary treatments for AS.
Currently, research suggests women are not more likely to have AS than men.
However, AS may be more common in women than once thought, and underdiagnosis could be preventing women from finding the answers and treatments they need.
Indeed, by the time women’s symptoms are identified and AS is diagnosed (typically more than 2 years after men get a diagnosis), they have a more advanced disease.
Arthritis is often considered a disease that comes about with age. But AS commonly occurs in people between ages 17 and 45 years. Some people receive a diagnosis as early as adolescence.
The age of onset is about the same in men and women. But women may get a diagnosis later because of the misconception that AS primarily affects men and because they might have initial symptoms that aren’t commonly thought of as AS, such as skin or gastrointestinal symptoms.
Having a family history of the disease increases a person’s chances of developing it. Many people with AS have a gene called HLA-B27. However, having this gene doesn’t mean you’ll develop AS.
The prevalence rate of HLA-B27 and developing AS varies among people based on their ethnicity.
According to the Spondylitits Association of America, about 95% of white people who have AS test positive for HLA-B27. About 80% of people with Mediterranean descent who have AS test positive for the gene. Only about 50% of African American people with AS test positive for this gene.
Likewise, in general, people with other inflammatory conditions, like Crohn’s disease, ulcerative colitis, or psoriasis, may have an increased risk of developing AS.
AS affects women during their reproductive years, but it does not appear to affect fertility.
Women with AS who are pregnant or trying to conceive can work with their doctors to find the right medications and to keep inflammation well managed.
Symptoms such as stiff spine and back pain can continue throughout pregnancy.
The disease may be more severe and arthritis more significant by the time women begin treatments.
One 2018 review found that women are less responsive to TNF inhibitors, a type of medication used to reduce inflammation in people with AS.
Medications can be used to help reduce pain and inflammation. Physical therapy may help improve posture, flexibility, and strength.
In severe cases, surgery may be necessary to repair or replace severely damaged joints.
Newer research suggests AS may be underdiagnosed in general and specifically in women.
Having once thought to be a condition that primarily affects men, we now know that more women have AS than once known.
Women tend to receive a diagnosis later than men, which delays treatment. Additionally, the disease may cause more inflammatory damage and symptoms for women than for men.
If you have symptoms of AS, such as persistent back or neck pain, see your primary care doctor as soon as possible.
If you’re a woman and experiencing back pain, joint pain, and other symptoms such as gastrointestinal or skin symptoms, it’s important that you talk with your doctor, even if your symptoms are mild.
You could have an underlying condition that might be causing all of your symptoms. It will take some time and testing to identify the patterns of your symptoms and test results so that you can get the right diagnosis.
Research is showing that women may have different symptoms than men and could be underdiagnosed.
There’s currently no cure for AS, but early detection and treatment can help alleviate pain and may prevent disease progression in both men and women.