Researchers previously thought AS developed mainly in men, and they haven’t thoroughly studied the condition in women. As a result, doctors often misdiagnose AS and other types of axial spondyloarthritis (axSpA) in women. Moreover, the medical community has a limited understanding of how the condition affects women — particularly what role hormonal changes and menstrual cycles might play in symptom flares.
Scientists do know that hormonal changes can cause flare-ups in other rheumatic conditions, like rheumatoid arthritis (RA) and psoriatic arthritis (PsA). More research is needed to better understand how hormones affect AS flares.
AS is a type of axSpA and is sometimes called radiographic axSpA. “Radiographic” means signs of the condition show up on X-rays. There’s also nonradiographic axSpA, which is believed to be a milder or earlier form of spondyloarthritis.
These closely related forms of inflammatory arthritis are generally understudied in women, leaving a large knowledge gap in how it affects them. Until recently, scientists thought that these conditions mostly occurred in men. Researchers have concluded that men and women experience AS symptoms differently, and some of these differences may relate to hormones.
The ovaries produce hormones including progesterone and estrogens such as estradiol. A few studies have looked at the effects of menstruation on hormone levels in women with AS. One small study found that estradiol levels were lower in menstruating women with active AS compared to those with inactive AS. Seven of the 17 participants received estrogen therapy, and their AS symptoms improved after an average of four months of treatment. While this was a small study, the results show that estrogen potentially plays a role in controlling AS symptoms and flares.
There is also some anecdotal evidence from MySpondylitisTeam members that their flares and symptoms worsen around their menstrual cycle. One member asked, “Question for the other ladies in the group, how many of you have flare-ups due to your menstrual cycle?” Another member responded, “I’ve never thought to track when it’s at its worst. I think I’ll start doing this. Thank you!”
How might the rise and fall of hormones during menstrual periods influence the ways women with spondylitis experience symptoms?
In AS, the sacroiliac joint found between the pelvis and base of the spine can become inflamed, causing lower back pain. Sacroiliac pain is also a symptom associated with menstruation. If a person experiences an AS flare during menstruation, their pain may be amplified more than usual.
Some other common AS symptoms that women experience may worsen during flares caused by menstruation. These include:
Many people take nonsteroidal anti-inflammatory drugs (NSAIDs) for pain management during AS flares and menstruation. NSAIDs include over-the-counter medications like ibuprofen and naproxen (such as Aleve or Naprosyn). Your doctor may prescribe corticosteroids (steroids) to treat spondylitis flares. Many people with spondylitis take disease-modifying antirheumatic drugs, such as biologic tumor necrosis factor (TNF) blockers, to reduce flares and control symptoms.
Studies have found that women with RA and PsA experience flares during their menstrual cycles. Researchers believe that estrogen and other hormones can influence the immune system and how the body perceives pain. During menstruation, estrogen levels drop, which may make a person more sensitive to pain. Studies have found that women also have more pain receptors than men, which may account for some differences in symptoms and pain.
One study involving mice found that estrogen may have an anti-inflammatory effect on spondyloarthritis. More research is needed to determine the effects of estrogen and other sex hormones in women with AS.
Menstruation symptoms may also be more severe in women with rheumatic diseases than in those without. A 2022 study looked at women with inflammatory arthritis, connective tissue diseases, and systemic vasculitis. Researchers asked participants about cycle patterns and the symptoms they experience. Those with rheumatic diseases reported more severe cramping, pain, and heavy bleeding during their teenage years and adulthood.
Another study investigated the effects of oral contraceptive pills (birth control pills) on the onset of AS. Researchers found that women who used birth control pills were significantly younger at their diagnosis compared to those who did not. However, there were no significant differences in disease severity, the onset of back pain, or medication use between the two groups.
If you’ve noticed your flares worsening around the time of your menstrual cycle, consider keeping a diary of your symptoms. Note when your cycle started, what symptoms you have, and any triggers you notice that may have set them off. Bring this diary to your next doctor’s visit and discuss your experiences with them, so they can better recommend treatments and suggestions for relief.
Read more about managing spondylitis flare-ups here.
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Have you noticed a relationship between your menstrual cycle and flare-ups of spondylitis symptoms? Share your experience in the comments below, or start a conversation by posting on your Activities page.