Heavy menstrual cycles and those anticoagulant drugs you’re taking

by Carolyn Thomas     @HeartSisters

Sara Wyen is a writer and founder of Blood Clot Recovery Network, a site that helps patients through the recovery process from deep vein thrombosis* or pulmonary embolism*. Her own story about a freakishly heavy period while taking her anticoagulant medication is a good one to share with any women you know who are prescribed these drugs.    .            .    

Sara was just 29, a runner (even a coach of other runners), eating right, and beginning what she calls her dream career – when her life was forever changed after an undetected blood clot in her leg suddenly broke free and lodged into her left lung. 

“I went from being happy, healthy and sure of the direction my life was taking to being gravely unhealthy, unsure of anything, and in the worst pain I could ever recall.”

Sara was discharged from the hospital on low molecular weight heparin blood thinning injections. Heparin is an anticoagulant drug that treats and prevents the formation of blood clots, often used in patients after heart attack, atrial fibrillation or any condition linked to an increased risk for blood clots.  Anticoagulants are sometimes called “blood thinners”. They don’t actually thin your blood, but they can help prevent blood clots from forming.

Sara now advises women who start taking anticoagulants that the first question to ask their doctors should be:

“Should my menstrual cycle be this heavy while taking anticoagulants?”

Sara says she worried if heavy periods would become a major issue for her, since she had already struggled for a long time with uncomfortable periods.

Although her periods were more frequent and slightly heavier at first following treatment for her blood clot, her menstrual cycle eventually returned to what had been “normal” for her – “unpredictable, but mostly manageable.”

But one day, her period arrived at the regular time yet significantly heavier than usual. Sara says she wasn’t alarmed – at first.

“My first thought was, ‘Good. I’ll get it all out of the way in a day or two!’  I began to grow more and more concerned as the third day of my cycle arrived, and the bleeding worsened. By that time, I was going through a 10-hour pad in less than one hour, and I was soaking through my clothes. My doctor instructed me to go immediately to the Emergency Department, which I did – now completely panicked about my situation. After several hours, it was determined that I had uncontrolled uterine bleeding. In my case, it was a period that wasn’t stopping. The cause was an INR level that was way too high, which I did not know about. I needed a reversal treatment (oral vitamin K), to help bring my INR back into a safe range. I am very fortunate that I did not need a blood transfusion. The Emergency staff told me repeatedly that it was good I came in when I did because the bleeding may not have stopped on its own.”

Sara explained that although this was a extremely scary experience which took several weeks of medication adjustments, blood draws, and ultimately bridging with injections to stabilize her INR, it’s a lesson that she takes very seriously.

And if she experiences abnormal bleeding like that again, she’s determined not to simply assume that it’s “just” her period – because now she knows that something could be seriously wrong.

Researchers have studied heavy menstrual bleeding  incidents like Sara’s as the use of anticoagulants and/or anti-platelet treatments has increased to reflect the growing number of pre-menopausal female patients with cardiovascular disease.

A 2019 study, for example, estimated that the prevalence of heavy menstrual bleeding in pre-menopausal women under age 50 increased from 18% before anti-clotting therapy to almost 30% afterwards. Yet cardiologists or vascular specialists caring for pre-menopausal patients may fail to refer these women to a gynecologist – or even ask about their menstrual problems.(1)

A European study led by Dutch cardiologist Dr. Angela Maas studied the dual anti-platelet therapy commonly prescribed to women after having a coronary stent implanted. This typically includes taking aspirin plus an anti-platelet drug like clopidogrel (Plavix) or ticagrelor (Brilinta).  Dr. Maas and her colleagues conclude that “treating pre-menopausal heart patients demands specific expertise and close collaboration between cardiologists and gynecologists.”  

And equally important, they recommend that more safety data on uterine bleeding in pre-menopausal women who are taking the newer “novel” anti-platelet drugs should be obtained before drugs are approved. This is a concern for all younger women taking these drugs, given how under-represented women have been in cardiac drug trialsSee also:  Is It Enough to Have “Enough” Women in Cardiac Studies?

Meanwhile, what do pre-menopausal women do if they experience abnormally heavy menstrual bleeding while taking these prescribed meds? There are solid reasons your physicians recommend your anticoagulants or anti-platelet drugs – stopping suddenly can lead to dangerous blood clots. But living with heavy menstrual bleeding can also carry both physical and psychological dangers of its own.

For more info, read about current drug, device or surgical treatment options on the Mayo Clinic website.  

Read Sara Wyen’s full story here – including four key questions she recommends all women who have heavy periods while taking blood thinners must ask their doctors.

Doing so, she believes, may prevent the frightening emergency interventions that she had to go through.

Image: Mabel Amber, Pixabay


  • deep vein thrombosis:  a serious condition that occurs when a blood clot forms in a vein deep inside your body – typically in the thigh or lower leg but may also occur in other areas
  • pulmonary embolism: a serious condition caused by a blockage in one of the arteries in your lungs, in most cases, caused by blood clots that travel tn the lungs from deep veins in the legs or other parts of the body (deep vein thrombosis)
  • anticoagulant medication:  (also called “blood thinners”) – they don’t actually thin your blood, but they can help prevent blood clots from forming
  • heparin: an anticoagulant that treats and prevents the formation of blood clots, often used in patients with heart attack or atrial fibrillation
  • INR:  (International Normalized Ratio) a measurement of how much time it takes for your blood to clot:  a low INR test result means your blood is not ‘thin’ enough or coagulates too easily and increases risk of developing a blood clot; a high INR result means your blood coagulates too slowly and increases the risk of bleeding
  • warfarin:  (brand names: Coumadin, Jantoven) an anticoagulant drug that’s used to prevent or treat blood clots, including deep venous thrombosis or pulmonary embolism, also used for blood clots that may be caused by certain heart conditions. Other newer anticoagulants include dabigitran (Pradaxa), rivaroxaban (Xarelto),  edoxaban (Lixiana or Savaysa) or apixaban (Eliquis) – also used by heart patients who are at moderate-to-high risk of a stroke
  • vitamin K:  a group of vitamins that your body needs for blood clotting and helping wounds to heal
  • anti-platelet drugs:  a class of drugs that inhibit the platelets in your blood from clumping together. Platelets are small particles that can stick together to form blood clots, potentially leading to heart attack and to the sudden clotting of a coronary stent. Aspirin (ASA or acetylsalicylic acid) is the most common antiplatelet drug;  at a low dose, aspirin reduces inflammation in the arteries, which is why doctors recommend taking aspirin if you think you’re having a heart attack.
Resources: Heart and Stroke Foundation, Mayo Clinic, National Heart Lung & Blood Institute, American Heart Association


1. Gu ZC et al. “The Management of Heavy Menstrual Bleeding After Percutaneous Coronary Intervention in a Woman of Reproductive Age.” Front Pharmacol. 2019; 9:1573. 2019 Jan 15.

2. Maas AH et al. “Practice Points in Gyne-Cardiology: Abnormal Uterine Bleeding in Premenopausal Women Taking Oral Anticoagulant or Antiplatelet Therapy.” Maturitas. 2015 Dec; 82(4):355-9.

Q: Have you experienced heavy periods associated with your anticoagulant meds?


NOTE FROM CAROLYN I wrote more about how cardiac medications affect women’s health in my book A Woman’s Guide to Living with Heart Disease (Johns Hopkins University Press). You can ask for this book at your local bookshop, or order it online (paperback, hardcover or e-book) at Amazon, or order it directly from Johns Hopkins University Press.  Save 30% by ordering this book directly from Johns Hopkins University Press, using their code HTWN . 

See also:

-Visit Sara Wyen’s site Blood Clot Recovery Network

A rock drummer’s take on atrial fibrillation

Why are women with atrial fibrillation treated differently?

What you need to know about your heart medications



13 thoughts on “Heavy menstrual cycles and those anticoagulant drugs you’re taking

  1. Reminds me of a discussion with my male cardiologist about my heavy flow while on coumadin (back in the day when I was first diagnosed and still menstruating).

    His response to my concerns? “You aren’t bleeding more. It’s just coming all at once.” To which I replied, “Spoken like a guy.”

    Only a man would see your entire blood flow happening all at once as “not a problem.”

    Liked by 1 person

    1. Oh, good lord, Wendy!


      If ever a cardiologist needed to refer a patient to a real live gynecologist. . .

      That is precisely the kind of knucklehead response that makes female heart patients seek out female cardiologists. . . which is not a bad thing EXCEPT it seems unfair to the many smart, compassionate male cardiologists I know who seem perfectly capable of not saying things like that out loud to worried women!

      Take care, stay safe. . . ♥


    2. Hi – I’m on warfarin. I’ve suffered from 2 pulmonary embolism – lungs and arteries. Was put on apixaban but ended up with another PE, put back on warfarin. It’s annoying cause you need to give blood every week but don’t get the app available at the doctor’s.

      I’ve going through my premenstrual, I’m 48 but also realised I’ve been suffering from heavy periods, but put it down to the warfarin – never mentioned to doctors. I also have a cyst on my ovaries – having regular checkups.

      It was very interesting to read about other people who are in the same boat.


  2. As a practicing gynecologist, I agree that we need to raise awareness of treatment for heavy periods, also known as menorrhagia.

    The Mayo Clinic link is fantastic, will hopefully spark conversations between women and their doctors to improve quality of life.

    Liked by 1 person

    1. Thank you Dr. Anne for this – I don’t know if you’ve seen this consensus document in the European Heart Journal (January 2021) by Dr. Angela Maas and her colleagues: a terrific overview of female-specific cardiac risk factors & treatment strategies – including a mention of “abnormal uterine bleeding” linked with taking anticoagulants.

      We know that abnormal uterine bleeding is not always reported by women experiencing symptoms, so the estimated prevalence varies wildly from 3% to 35% of all women! This seems like far too many women are keeping quiet about this – so YES we do need to raise awareness!

      Thanks for your comment – take care out there. . . ♥


  3. Hello. I too had numerous pulmonary emboli when I was in my mid 50’s. I was prescribed a blood thinner and was monitored by my doctor – no hospitalization. A few months after that incident, I noticed my periods were ridiculously heavy. I knew this wasn’t right as I was nearing the end of menopause.

    I had it checked out and they did a biopsy. They discovered I had stage 1 cervical cancer. I had a total hysterectomy with salpingo-oophorectomy – everything was removed. No more slow course through menopause – I crashed into full menopause.

    I have since been diagnosed with heart failure. Luckily my gynecologist is still following me and I finally have a good cardiologist. (I have left out a lot of the horror show and the lackadaisical treatment I had received before). I am thankful I am doing okay.

    Thank you for your blog. You have no idea what a relief it is to read about others’ stories and realize you are not alone. Thank you !!

    Liked by 1 person

    1. Hello Anita – it sounds like you have exceeded your maximum lifetime quota of medical crises! I hope you are feeling better after everything you’ve been through.

      Your story (I can only imagine what you’ve left out – you are not alone for sure!!) is such a good example of WHY it’s critically important not to dismiss heavy periods, but to listen to that little inside voice that tells us this is not “normal”.

      I also like to think that somebody somewhere is reading your comment right now and will call her doctor first thing tomorrow because of learning what happened to YOU.

      So thank YOU for weighing in here. Take care, stay safe out there. . . ♥

      Liked by 1 person

  4. I’m post menopausal but remember having periods so heavy I became anemic and needed iron supplements and I wasn’t on blood thinners then.
    I am on warfarin and aspirin now and I am followed by the Coagulation Team- pharmacists that specialize in making sure my INR remains within therapeutic levels at all times.

    The newer “blood thinners” don’t require such close monitoring like warfarin does, but they also cannot be reversed with vitamin K. So I would imagine an emergency with one of those drugs could be very difficult.

    Knowing our bodies, understanding our diseases and tag teaming with specialists seems to be our job until the medicine becomes a more perfect practice.

    Thanks for the interesting article.

    Liked by 1 person

    1. Hi Jill – thanks for reminding us that heavy periods can result in serious health consequences – like anemia. Medical care is so often a delicate balancing act between therapy that works vs side effects that can harm.

      I wonder if all patients taking anticoagulants are closely followed by a Coagulation Team like yours. I know this monitoring is routinely done after the initial diagnosis – but does it go on forever?

      I know that the most popular selling points to patients for the newer “novel” anticoagulants when they were first launched as possible replacements for warfarin were: 1. lower risk of stroke in atrial fibrillation, and 2. patients didn’t require the ongoing monitoring that warfarin did.

      But there was also that initial fear of how to stop bleeding associated with those drugs (not just increased menstrual bleeding but gastrointestinal bleeding – and worse). A dose of vitamin K didn’t work on those novel anticoagulants! Since 2018, however, antidotes that DO work to reverse bleeding have been approved by the FDA for patients taking Eliquis, Xarelto, Svaysa, Pradaxa.

      You’re so right Jill – we all need to be part of that tag team with our specialists!

      Take care, and stay safe. . . ♥


      1. I belong to Kaiser HMO and they do a lot of research on their patients to monitor quality of care. It used to be that the cardiologists did all the coagulation monitoring but that was a huge draw on their time with so many people on anti-coagulants. Things slipped through the cracks. We have a coagulation team of pharmacists, and a cardiac risk pharmacy team that works with statin intolerance etc.

        Warfarin monitoring is a pain sometimes…. every invasive test like colonoscopy or kidney biopsy you have to go off for days and then get back on and have your blood drawn a half dozen times. I’m on warfarin instead of one of the newer ones because I’m on Verapamil and I guess they don’t play well together.

        Anemia would be a great topic … I’m getting iron infusions right now for borderline low Hgb and iron stores. I wonder if lab “normal” values should be reconsidered in cardiac patients with fatigue, shortness of breath and exercise intolerance. Maybe we need a higher Hgb and HCT and ferritin to compensate for our cardiac status?

        I guess I’ll be my own experiment LOL I’ll let you know how it goes next month after my 4 iron infusions.

        Liked by 1 person

  5. Hello: First of all, thank you thank you thank you for all the work you do in this area. I’m a big fan and recommender of your blog as well as your book.

    I was also bothered by very heavy menstrual periods, 15 years before I had my heart event.

    Eventually, I found my way to a gynecologist who did an experimental procedure called endometrial ablation. I had to politic to have the procedure covered by medical insurance.

    It changed my life. I do not think this was related to my heart event. And, of course, this is now considered acceptable for pre-procedure for women with heavy periods.

    Just wanted to chime in, as well as to say, again, thank you to you!

    Best, in health,


    P.S. Perhaps not a place for this, but would you consider looking at how people without a religious belief help themselves to deal with their heart condition?

    Liked by 1 person

    1. Hello Susan and thanks so much for your kind words.

      Interesting – and annoying! – that you had to fight to have your ablation procedure approved by your insurance company. If men were the ones who needed this ‘life-changing’ procedure, I wonder if they would have have to beg for it. . .

      Thank you also for your suggestion of writing about how religion does – or does not – impact heart patient recuperation. I’m going to think about that (as a “recovering catholic” with no religious affiliation at all anymore who has still somehow managed to deal with two cardiac conditions!)

      Take care – stay safe out there. . . ♥


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