Menstrual Health
Why Are My Periods So Heavy?
We're not doctors. This page collects what the published research actually says about heavy periods and one cause that gets missed, so you have something concrete to bring to your own doctor.
Soaking through a pad or tampon in under two hours, passing clots bigger than a quarter, or bleeding for more than seven days is usually chalked up to the standard list: fibroids, hormonal imbalance, polyps, or just "some people's periods are heavier than others." Those are all real and worth ruling out. But there's a cause that shows up far more often than most people expect, and it rarely comes up in a first conversation with a gynecologist.
The Hypermobility Link Behind Heavy Periods
Heavy menstrual bleeding, medically called menorrhagia, is one of the most consistently documented symptoms in hypermobile Ehlers-Danlos syndrome (hEDS). A 2016 study of 386 women with hEDS, published in Orphanet Journal of Rare Diseases, found menorrhagia in 76% of the group. A newer study of 52 patients found it in 88%, and half of that group had bleeding severe enough to require an ER visit, a blood transfusion, or surgery.
Heavy periods are common in the general population too, so this alone isn't a red flag. What's notable is how much higher the rate runs in hEDS compared to what's typically assumed, and how rarely a heavy period gets connected back to connective tissue at all. The leading explanation is that the same tissue fragility affecting joints and skin in hEDS also affects blood vessels, making them more prone to bleeding.
One thing the research doesn't yet answer directly: whether heavy bleeding in hEDS reliably leads to iron deficiency. No peer-reviewed study has measured ferritin levels specifically in hEDS patients, or tested whether treating iron deficiency improves hEDS-specific symptoms. What we do know comes from the general population: a trial in iron-deficient, fatigued women found that IV iron reduced fatigue in 65.3% of participants, compared with 52.7% on placebo. If heavy periods and fatigue are both showing up for you, a ferritin test is a reasonable thing to ask for, not because the hEDS link is proven, but because it's a cheap, low-risk check for something treatable.
Read more on the hub page
Heavy Periods, Iron Deficiency, and Cycle-Linked Joint Pain in Hypermobility
Where to go from here
If you have heavy periods and think joint pain, frequent sprains, or unusually flexible joints might be part of the same picture, our Menstrual and Hormonal Health page goes deeper into the bleeding data, the iron question, and how cycle timing can affect joint laxity. It's not a diagnosis, but it's a starting point for a more specific conversation with your doctor.
Sources referenced on this page
- 01Hugon-Rodin et al., "Gynecologic symptoms and the influence on reproductive life in 386 women with hypermobile Ehlers-Danlos syndrome," Orphanet Journal of Rare Diseases (2016) (link not yet sourced)
- 02Study of 52 hEDS patients on menorrhagia prevalence and severity (link not yet sourced)
- 03Randomized trial of IV iron vs. placebo in iron-deficient, fatigued women (general population) (link not yet sourced)