Ask a Scientist: Why Am I So Tired During My Period?

The Scientist: Lauren F. Streicher, M.D., Clinical Associate Professor of Obstetrics and Gynecology at Northwestern University’s Feinberg School of Medicine, and author of Sex Rx: Hormones, Health, and Your Best Self Ever.

The Answer: There isn’t any hormonal reason some women feel totally drained during their period. It’s totally normal to feel mood swings or crave sweets or salt, but nothing about menstruation itself should be making you feel tired. Instead, a few of your habits, which are a reaction to how crummy you feel when you’re menstruating, could be contributing to your low energy levels.

Some women have trouble getting a good night’s sleep during that time of the month. Cramps and a heavy flow can both interrupt a smooth night of slumber, whether you’re waking up in pain, going to the bathroom to change your tampon, or getting up to pop some pain meds. Also, many women avoid exercise when they have their period. Sitting around and not exercising tends to make you feel more lazy and lethargic at any time of the month.



On top of all this, reaching for a heaping bowl of mac ‘n cheese isn’t the best way to sustain your energy. Making poor food choices, which many of us tend to do when we’re craving a little extra comfort, can just make you feel even more sluggish. (Here are some tips on what to eat during your period instead!)

The only real medical reason you could be unusually tired during your period is if you have anemia, which is an iron deficiency. For some women who are anemic and have a very heavy period, the first day can be a doozy.  However, this group is in the minority. If you know you’re treating your body right and are still walking around like a zombie during that time of the month, see your doctor to find out what’s up. A simple blood test can reveal if you’re anemic and it’s very easy to treat with iron pills or the addition of more iron-rich foods to your diet.

Bottom line: Figure out what’s draining your energy and fix it. You should be able to have your period without feeling exhausted.

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  • Lucy Madeline

    This article is ridiculous and patently false. I wish #LiveTweetYourPeriod was happening when this came out. There are many reasons women may feel tired on their period that don’t have to do with sitting around and “being lazy” or “scarfing” down bathtub sized bowl of mac-n-cheese (which, by the way, we don’t do because we’re looking for comfort. There are hormonal, physiological reasons women have cravings on their periods).There are PROFOUND hormonal fluctuations in one menstrual cycle. There is also a slight drop in blood pressure during menses which can be exhausting. Fatigue during days 1-3 of menstruation is one of the MOST COMMON side-effects women report. “The only real medical reason you could be unusually tired during your period.” ARE YOU JOKING?! Nice use of the word “real.” I’m surprised the reader wasn’t accused of being hysterical. The irresponsibility of using the phrase “the only medical reason” when answering a girl’s question about her period when you do not have the research to back what you are saying is shocking.

    This kind of out-dated non-science is hurtful to women and girls. Do some reading on the issue. Or, stick to reviewing make-up and “covering home decor.” Maybe the structure of the article came from the editor, but regardless, please, do not spread shaming, false, misinformation.

    • Lisa Glam

      I agree. I eat mac and cheese twice a year (thanksgiving and Christmas) and take vitamins everyday. I am also a runner. I rarely have cravings during my period and if I do, it’s my right! I am sick of these so called medical people minimizing women’s conditions as if we are some sort of weak, lazy complainers. If you don’t know the answer, research it! But don’t act like we are crazy because we are having symptoms you don’t understand!

      • soliel67

        Since you are a runner…do you have the same get up and go on your period as when you don’t? I bet you don’t. Like me.

        • Lisa Glam

          Not understanding your question fully. I try to avoid running on my period because my flow is too heavy and running makes it worse. I have fibroids so I choose to lift weights more during that time.

          • soliel67

            I am sorry. I understand. I, too, often feel tired on my period.

        • Vivian

          Exactly. I can’t even get myself to go for a walk right now, as I’m completely exhausted.

        • Janine I love Halloween Rus

          i do at track.

      • Lindsay

        This article is totally BS!

    • Laura

      I agree completely, Lucy.

    • EdyeNicolesMakeup

      THANK YOU.

    • Jesse Hoffman

      Thank you Lucy! Also I agree.

  • Jana

    I have to agree with Lucy – this article is not supported by science

  • LaTasha

    I also agree with Lucy. There are definitely some hormonal fluctuations going on because I’m not just sleepy, I am fatigued. I was fine yesterday before it started and today, I’m so tired I can barely function. I didn’t have “comfort food” for lunch, I had a chopped kale salad, which is what I usually have. I came to this site looking for answers. I’m not sure what this author is basing her information on…it’s certainly not the truth…

    • Samantha Lane

      Plus one. There is no useful information about menatrual fatigue and all articles glibly attribute it to poor diet or lack of exercise.

  • Tina Stance

    This article is shameful. In other words, you’re accusing the reader of being a lazy oaf with crappy food habits. Thanks loads.

    • Suzanne

      I know I am late to reply – but I kind of felt the same way. I eat so well and I always have. I’m a very healthy weight – lean and toned. I exercise and have since I was a child (I’m now 40). It is so obviously hormonal when you feel this exhaustion. I guess women that do not experience it simply cannot understand.

      • yrsa

        Yep. I agree. This egocentricity has to stop. Just because it doesn’t happen to you doesn’t mean you can apply your case to everyone else. Please lady, this 2016. Learn to science.

  • Christina G.

    This is a horrible article. One of the main reasons for fatigue is the drop in iron levels from blood loss. That is a medical fact and the FIRST thing doctors usually look at. While sleep habits and diet may contribute to tiredness, they do not contribute to period-specific fatigue, which is totally different then being tired! My advice to the reader would be to talk to a doctor and get tested during your period for iron deficiency. Don’t just start taking supplements. I did that and I ended up feeling super funny because my body natually produces too much iron. There are also a number of hormonal imbalances that are causing PMS. Birth control helps lessen this in some women. My

    Also, taking 5,000mg of Vitamin D3 can significantly raise energy levels and help take the edge off. I take it every day.

    Hope this helps!

    • http://www.mysteepedteaparty.com/Monique Monique Lynn Thompson

      I came across this on google and was hoping that the author wasn’t going to reference a medical background. Low Iron levels was the first thing that came to mind when I think of exhaustion and menstration. I’m surprised this was written by a woman and even more surprised that she opted to write about this particular subject without doing ten seconds of medical research.

      • Christina G.

        I couldn’t agree more. It just goes to show that you need to reference multiple sources before taking anything seriously on the internet. You can claim to be anyone you want but it doesn’t mean you know what you a re talking about. It honestly sounds like this article was written by a man.

      • the fox forgot

        Google got me here too. I’m trying to get it taken down as the “answer” snipped that pops up when you google “fired on period”. No bueno!

  • Madigan1323

    I agree with everyone here. This article is pure crap. The fact that it was both written by a woman and came up at the top of my google search results is alarming.

  • Mmarple26

    What a wretched article. Completely unhelpful and borderline misogynistic. Thanks for nothing.

  • Last Resort

    This needs to be taken offline. What an offensive and idiotic piece of writing.

  • topcommenter

    I’m glad I wasn’t alone when everyone else rolled their eyes as soon as they read this. Perhaps the person who wrote the article is trying to be taken seriously in the boys club of M.Ds and so feels the need to play the “it’s not your period, it’s you” card, because women are just whiners who can’t chock it up and get shit done on those totally normal days where you gush blood through your hoohah.

    My CEO wife can’t seem to figure out why she’s suddenly dozing off two hours earlier than normal or having so much trouble getting out of bed, until she suddenly remembers, oh right, oh right… she’s on her period. Trust me, she’s not trying to make excuses and get a doctors note so she can sleep in and “skip work”.

    Can we get a real M.D in the room to answer what’s going on? What a joke.

    • Suzanne

      Thank you. I’m a small business owner (if I don’t work, I don’t make money). I get so tired – and I’m NOT lazy and I eat really well. It’s just awful to feel so exhausted and as someone with an abundance of energy all but 3 days of the month, I too found this article a tad offensive.

    • cheeze.wiz

      i have a male dr Abbas he’s never said my fatigue is because I’m lazy.

  • Mariah Brodie

    Add the fact that your body is actually losing blood…. BLOOD, people! And it is going to have to remanufacture an equal supply once you’ve finished your period. Blood contains many necessary nutrients like iron, sugars, sodium, protein; all of which explains certain cravings(not an Olympic sized bowl of Mac’n’cheese). Add in the other fact of your body literally contracting and squeezing out one of your internal organs,and it can put you out of commission for a little while. It’s like a smaller form of childbirth. All of the same muscles and organs contract and just think of how strenuous childbirth is. Even on a small scale, that will make you pretty tired, don’t ya think?

    • Suzanne

      Well said. YES – it makes me exhausted for 2-3 days – every single month. I like the way you explained it. Society used to have respect for a woman’s menstrual symptoms. So many women are on the pill (no judgment) and do not have the symptoms of a, “real period”. I think that is a big reason why so many people have forgotten how many symptoms a woman can have for a few days. I have learned to carry on, but take it a bit easy for those few days.

      • Esther Sorenson

        I’m on the pill and I have a period at the end of each cycle. There are certain birth control that stop periods, but not my pill Blisovi Fe.

  • GabrielleD

    … waaaait… so if I eat right, exercise regularly, and STILL I feel lethargic, that means something is wrong with me. (makes worried noises)

    Is THIS what this physician is trying to aim for? Because it’s not comforting at all.

  • Pat Hume

    so sick of women feeling guilted into only eating healthy at their worst time of the month!!!

  • miramar30a

    This article written by a “scientist” is offensive on so many levels, my PMS IRRITABILITY factor is shooting up. The question asks about PRE menstrual fatigue. Some of the reasons the “scientist” gives are disturbed sleep caused by cramps, etc. Um…..that’s “D” MS. There’s nothing pre- about being on your period. Where’d you get your doctoral degree genius?

    In my experience. The fatigue comes on suddenly like I’ve been hit by a freight train. And by the way, I am anemic due to heavy flow – but it’s a different fatigue. Once I start my period – it’s like a light switch and I’m ready to clean house, run errands, work a 12 hour day… It affects everyone differently but I strongly believe, in my unscientific opinion (which is why I’m googling scientific explanations for PRE menstrual fatigue) that it’s caused by hormonal fluctuations. Let me do some further research after I finish this heaping bowl of mac and cheese. . WHICH by the way can be healthy if you prepare it correctly. Low carb pasta with low fat cheddar and cottage cheese mixed in with eggs to bind and a few veggies? Comforting AND healthy.

    Trust that I will NOT be buying “Dr” Streicher’s book. Such a joke. Going to the real scientific literature now to read studies on PMS and fatigue for an *evidence based* answer.

    • Kelli

      I have often described my fatigue the same way- it comes out of nowhere and is literally like flipping a switch! I’ve been up and active one minute and the next basically asleep on the couch. This article is such a joke.

  • Jauly

    Some of the above is true, if you have ALWAYS become tried while menstruating then by all means don’t worry about it. Yet for me, I’ve been with this for 20 years now and only just recently started to become weak and sleepy. I reas this blog and did speak to my doctor. Thankfully I didn’t rely on just the people commenting. For me, even though I’m active and eat right I found out I have a unusual level in white blood cells, further tests are being done. So no, it is not ALWAYS normal for your body to change over a 3 week period. You know your body the best you can and if anything is going on with it the makes you uncomfortable you do need to speak to someone who’s research and studied in the matter. We do not know our bodies best, if we did we would never have to be treated for anything. A lot of reasons could spike up for us women during our period, but about 85% of the time it’s a natural bump in the road. As my doctor said, a lot of women whom had cancer experienced changes previously with how they felt during their cycle but always thought it to be normal changes due to our hormones levels slightly changing. Like for me I find it really odd when women have mood swings while on their period, I myself am even more cheerful and kind during mine, yet as of lately I can add even more sleepy on top of that. Best of wishes to all women.

  • tayriley

    uh, no. fatigue is totally normal during period. i always sleep more the first few days of my period. diet doesnt change. exercise doesnt change. this article is full of shit.

  • Sickofit74

    This is pure bullshit.

  • CR444

    This is ridiculous. I’m an extremely active person, and extremely health conscious. When my period starts I get cramps, a fever, extremely introverted and sensitive to stimulus. I also get nauseous to the point of vomiting. Not “lazy.” Jesus. So glad how many ladies called out this “expert.”

  • balance

    Oh good its unanimous. This article is phony boloney!!!! I thought this must be a man talking.

  • Hannah Dougherty

    You CAN be tired due to your hormones during your period. I think I read it in Cosmo or Glamour but other sites have similar articles too. It has to do with the sudden surge of testosterone (which causes us to be horny, break out, and makes our hair on our upper lip more noticeable) and then drop in testosterone levels that happens as our period starts. That doesn’t mean you shouldn’t eat right, exercise, or try popping a Midol or two to help ease the side effects but it also doesn’t mean you are lazy and make poor life choices Heck, I work 3 jobs, don’t you dare call me lazy.

  • robingee

    I’m exhausted during mine because I have heavy blood loss. I take iron sups but I am still anemic and my head is on fire and I can barely function. It’s nothing to do with my bad habits, it happens the first 2 days of menses, every month since I was 16.

  • Svet Kiss

    I don’t buy any of it. My friend who is very active and in her late 20s Her and I are avid runners. I am in my 40s. We both work physical jobs. She is single and I am married and have 6 children. My friend is very health concsious. Does not indulge in junk food. I am pretty health concsious, but on occasion indulge on junk food. We get good night sleep. So why is it that both of us in spite the age differences, Life styles, feel like falling over two days only!!! right before the menses? I must add I am very energetic for the rest of the month, including during my period, running 5-10 clicks and continuing working

  • Christina Roth

    I have to agree with all of these comments. I mean come on. I have ADHD with significant hyperactivity and when I get my period I can barely move even if I am not in a lot of pain I’m so exhausted! I sleep 9 or 10 hours a night and sometimes still feel like I need to nap during the day! I am so surprised that this article is written by a woman. How does she not notice this when she has her period? I came to this site for a legitimate answer about what hormones cause this phenomenon and I get the answer, “Oh it’s because you are lazy and don’t exercise during your period.” Which brings me to another point, if you have enough energy and are able to exercise during your period, I don’t think that your periods are normal at all. I have to force myself to just go shopping and walk around on my first few days. I also have to take medicine immediately at the first moment I feel a little bit of blood otherwise I will be curled up in a ball on the floor from the pain. We need to start telling women that it’s ok to be women and that this time of the month sucks. It really is ok to spoil ourselves with a little extra sleep and a heating pad if we need to.

  • Victoria Franklin

    I’m sorry, but whoever wrote this BS tiny article is a complete bitch. Screw you and no thanks for being any help or being supportive.

  • Victoria Franklin

    I’m sorry but whoever wrote this tiny BS article is a complete bitch. Don’t confidently claim you’re a scientist and then spout ridiculous crap that’s minimizing issues that women naturally have with their bodies and blaming them for it. As someone who has suffered from fatigue and weakness from periods, even when I was taking care of myself, I find everything written here insulting and completely unhelpful. No thanks for nothing.

  • soliel67

    I don’t believe this. It’s contrary to everything I’ve read and my own experience. I’ve read the drop in estrogen makes you tired and after your period you slowly regain it. Also, I ate impeccably before this period as I usually do. I’ve been exercising a lot. But suddenly I feel tired…oops! Period started. Bingo. Has nothing to do with food or exercise just drop in estrogen.

  • Ami Merveilleux

    Blame the woman. Typical. This statement from the article above makes me want to throw my computer out the window, “There isn’t any hormonal reason some women feel totally drained during their period.”

    WHO comes up with this garbage? You can’t be serious. Then blame it on what the woman is doing, “Oh well sweetheart if you wouldn’t snarf down that bag of Cheetos during your period you wouldn’t be so dang tired!”

    WHAT DO YOU THINK CAUSES ALL OF THIS??? Hormones. Wow. This article just wastes bandwidth.

  • Ami Merveilleux

    Each time I read this article, the more ridiculous it is. Throughout history the woman has been continually blamed for this whole, ‘period’ business. Hysterectomies were initially devised because doctors, (men) decided that a woman’s uterus was making her hysterical.

    I sincerely hope that the author of this piece of swill reads our comments and understands the complete BOTCH of an article she has written.

  • Lindsay Berry

    Seriously? My husband can testify to my change during this time of the month. I am currently laying in bed @ 3:15 pm on a Sunday. I am exhausted. I am really wishing I had the energy to get out of bed and clean the house. Something tells me a man wrote this, because my mind cant wrap around how a woman could write this article with experiencing a period. I don’t like mac & cheese either, that is my husband’s taste in food.

  • Alison

    This article is awful and perpetuates the oppression of women. It must have been written by a misogynisit and I cannot believe that someone could actually feel good about themselves writing such a shameful, degrading, and oppressive article. Disgusting. Do not go misinforming!!

  • Kimberly

    This is completely incorrect. I don’t know a single woman that eats junk food and sits around being lazy during her period. Not one. In fact, most women try to live a healthier lifestyle during their periods (plenty of sleep at night, exercise, lots of water, vitamin supplements and plenty of healthy foods). Most women try to avoid trashy food during their period because it makes us feel worse. Hormonal fluctuations ABSOLUTELY can cause lethergy in healthy women let alone those with a hectic lifestyle, gynecological conditions or other health issues. Blood loss during your period can also lead to lethergy, and in some women, anemia due to low iron levels. Side effects during menstruation such as breast tenderness, gastrointestinal changes, bloating, cramping, back aches, migraines, dizziness, etc. (this list goes on) can wipe women out as well. This article is nonsense and is completely unfair to blame women for feeling tired during their periods.

  • https://www.ebates.com/r/NATCAR12?eeid=28187 Nataly Carbonell

    So am I a lazy fuck or is it just my period?

  • the fox forgot

    This should not be the first snippet that comes up as the answer when you google “tired on period”. Stop the lies!!!

  • Stephani

    Why do I feel like the information used to write this article was given by a male that sees tiredness as an excuse women state in order to complain ?
    Anyone who had taken an entry level physiology class can tell you that this is completely false.

  • anonymous

    For anyone looking for info on this subject. This thankfully was not the first one I came across. I saw several other articles also written by doctors who explained it is common and normal to feel unusually tired the first few days of a period due to a sudden drop in oestrogen. You should start to feel better after two-three days. The advice I’ve read is that you should get checked for anaemia if it isn’t limited to the first few days, and especially if you have heavy periods. If you don’t have heavy periods and feel fine most days but tired on the first couple of your period, it’s probably not anaemia.

    Source: Every article except this one.

  • KathrynElizabethMorgan

    As the mother of 4 girls and as a girl myself this article is absolutely absurd! Must have been written by a man.

  • Rattner

    Complete and utter bollocks. Fuck you, whoever wrote this.

  • MotivationalMe

    This was written by a man. First off if you have heavy menses you are gonna feel lethargic because u are losing blood and your iron levels are what creates energy in the body. This article pissed me off

  • River

    Amy Marturana, this piece is incredibly irresponsible and completely ridiculous.
    Open a book, speak to a Doctor.. knowledge is power.

  • Stephanie Turner

    What a joke. I don’t even need to track my period to know when it’s coming. I suddenly feel so exhausted and as though I haven’t slept in days. I also crave Pringles and peanut M&Ms so badly, even though I don’t typically have a sweet tooth or enjoy salt. I never otherwise feel this way. It’s because estrogen and progesterone plummet right before your period. This article is just another way to shame and belittle women and deny their experiences.

  • http://www.digitalempireunleashed.com Juanita Dailey

    What? Seriously… There is obviously a connection when this happens all of the time. Please get your facts straight before posting something like this.

  • Rachel Cox

    I workout everyday, period or not. I eat a very healthy and balanced diet, I have even cut sugar out almost completely (can’t cut the sugar that’s naturally in things), I am not anemic (already been tested), but as soon as my period comes around, I feel like I suddenly haven’t slept in a month, and I don’t ever wake up in middle of night for anything…so you sure it isn’t hormones? LOL

  • Maria Jensen

    Amy Marturana Where did you get your Obstetrics and Gynaecology Degree from. I would suggest people read scholarly articles concerning these uestions. Look up Scholarly Articles Menstrual Fatigue, Iron deficiency, Chronic Fatigue, Underlining Medical Conditions, Menorrhagia, Endometriosis, Diet. Do proper research. This article is condescending at best.

  • Parp

    I know it’s pointless to comment on such an old article, but I’m disappointed this garbage is a top google result. I’m just looking for ways to cope.

  • Jeff

    Stupid article! I was out like a rock all night last night and woke up feeling lethargic due to my period. This is usually how I feel once a month regardless of my eating or exercise habits. Susan (on hubbys account)

  • Kiamolee

    Ummm what kind of crap is this article? How about low iron from blood loss. Some women experience low blood pressure during this time. Pain is exhausting on your system and yes hormonal imbalances and changed can affect energy levels. Telling me I’m lazy? Girl stop writing.

  • Marzee Hamed

    I was on holiday last month and usually woke up at 8 am , on the third day of my period I couldn’t wake up, I felt drugged, luckily I woke up at 11 am and skipped breakfast because it was over at the hotel. I never connected it to my period and just thought I was exhausted because we were up early the day before and busy during the day. Now a month later , first day of period and I got the feeling again, this time I slept till 5 pm almost a whole day . Has anyone else experienced this?

  • Jess Best

    The comments were more informative than the actual article.

  • soliel67

    From what I understand when the period hits there is a huge drop in estrogen which makes us tired. About a week after the start of the period the estrogen builds up to feeling like yourself again. There was a charge I saw called “hormonology” which laid it out. It said plan your most demanding jobs around your period if you can. For instance don’t move during your period.

  • Christina Spears

    Hey guys
    I’ve just started my period today and I’m totally wiped out and going to bed early. So is this article pretty much saying we’re lazy and our food habits are to blame? Not really, cause I crave chocolate during my period

  • Janine I love Halloween Rus

    very interesting

  • Alicia Nicole Montanez

    What a horrible article. This is completely false. I can’t believe this came up in the top 4 of my search results. And to make matters worse, a woman wrote it. You should be ashamed of yourself. You do realize that your article is not based on facts right? If it was, you should have mentioned that a possible thyroid issue can also be a cause of symptoms.

    You are a horrible writer. You need to go back to school and learn something.

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