Resources for Understanding Why You Have No Period.

There are common misconceptions about how a woman can lose her period. “Everyone” seems to know that women who have eating disorders or are Olympic-level athletes commonly have no period. What is much less well-known, however, is that periods can go missing at much less extreme levels of calorie/food group restriction and exercise.

A big part of our book, No Period. Now What? is the survey of over 300 women that we completed, asking a variety of questions about factors leading to hypothalamic amenorrhea, steps taken to recover, and recovery success (as well as trying to get pregnant, pregnancy, and beyond.) From that survey we were able to get a much better picture of the range of women affected by missing periods.

Our last few posts have discussed the factors involved in acquiring HA: exercise and undereating, weight/weight loss, stress, and genetics, and also about how women who are not avid exercisers or “underweight” can have HA. But those posts can take a while to read through. So we put together an information sheet to help educate those with no period / hypothalamic amenorrhea, as well as any others who might be interested (e.g. doctors, family members). In addition, we’re making the first chapter of our book, which describes the basics of hypothalamic amenorrhea, available for download. Enter your email address to receive an email with a download link for both. Please feel free to share the files: for example with your doctors, other women with HA, and friends or family members who might not understand why your periods are missing.



Update: I recently put together a video explaining these five factors, in case you prefer visual learning.

Hope this helps!!  Any questions, please comment on this post or use the contact form!


In case you’re interested, references for the information sheet are listed below.

Understanding Hypothalamic Amenorrhea Information Sheet References

Causes of amenorrhea:

Effects of underfueling:

  • Wade GN, Jones JE. “Neuroendocrinology of Nutritional Infertility.” American
    Journal of Physiology: Regulatory, Integrative and Comparative Physiology. 287(6) 2004:
    R1277-1296. doi: 10.1152/ajpregu.00475.2004
  • “Balancing Calories to Manage Weight.” In Dietary Guidlines for Americans, 2010.
    7th Edition ed. Washington, D.C.: U.S. Department of Agriculture and U.S. Department
    of Health and Human Services, 2010.

Exercise (stress) and hypothalamic amenorrhea:

  • Hill EE, et al. “Exercise and Circulating Cortisol Levels: The Intensity Threshold
    Effect.” Journal of Endocrinological Investigation. 31(7) 2008: 587-91. doi: 10.1007/BF03345606
  • Loucks AB, et al. “Alterations in the Hypothalamic-Pituitary-Ovarian and the
    Hypothalamic-Pituitary-Adrenal Axes in Athletic Women.” The Journal of Clinical
    Endocrinology & Metabolism. 68(2) 1989: 402-11. doi: 10.1210/jcem-68-2-402
  • Mastorakos GM, et al. “Exercise and the Stress System.” Hormones. 4(2) 2005:

Stress and hypothalamic amenorrhea:

  • Berga SL, et al. “Recovery of Ovarian Activity in Women with Functional
    Hypothalamic Amenorrhea Who Were Treated with Cognitive Behavior Therapy.”
    Fertility and Sterility. 80(4) 2003: 976-81. doi: 10.1016/S0015-0282(03)01124-5
  • Biller MK, et al. “Abnomal Cortisol Secretion and Responses to Corticotropin-
    Releasing Hormone in Women with Hypothalamic Amenorrhea.” Journal of
    Clinical Endocrinology & Metabolism. 70(2) 1990: 311-17. doi: 10.1210/jcem-70-2-311
  • Brundu B. “Increased Cortisol in the Cerebrospinal Fluid of Women with Functional
    Hypothalamic Amenorrhea.” Journal of Clinical Endocrinology & Metabolism.
    91(4) 2006: 1561-565. doi: 10.1210/jc.2005-2422


  • Caronia LM, et al. “A Genetic Basis for Functional Hypothalamic Amenorrhea.”
    The New England Journal of Medicine. 364(3) 2011: 215-25. doi: 10.1056/
  • Gianetti E, et al. “When genetic load does not correlate with phenotypic spectrum: lessons from the GnRH receptor (GNRHR).” Journal of Clinical Endocrinology & Metabolism. 97(9) 2012: E1798-807. doi: 10.1210/jc.2012-1264

Factors in a missing period / no period, Part 1

There are five factors that play into when a woman stops ovulating and has no period due to hypothalamic amenorrhea, aka HA. The most common combination is undereating/underfueling, and overexercising/overtraining. But… that is far from the only way to get HA. Stress alone can cause one to miss a period; add in a little bit of food restriction or increase in exercise, and that one missed period turns into many. Or perhaps you were in a larger body at one point and lost more than 10 lb to get to a “normal” weight… that alone can cause missing periods in some, but add that weight loss to food group restriction, like a low-carb or low-fat diet, and boom. No periods. (There are other reasons behind no periods, of course, one of the most common being PCOS… all of this is discussed in more detail in our book).

Let’s go through the factors one by one, and I’ll share some more data from our survey respondents with you.

1. Exercise

The first factor we’ll consider is exercise.  I shared last week that the amount of exercise can vary widely among women with HA, although we do tend to exercise more than four days a week and for an hour or more at a time. What’s interesting, though, is when you look at exercise intensity. That is another part of the equation. We asked our survey respondents about the intensity of their exercise when their periods were missing versus prior to that, when periods were normal.

Average exercise intensity when women experience hypothalamic amenorrhea versus prior

The two lines show exercise intensity on a scale where 0 is sitting, 5 is moderate exercise like a fast walk or slow jog, heartrate in the 140-149 range; 10 is a personal record pace, heartrate 190+. Each point shows the percentage of 278 women who described the average intensity of exercise they performed prior to having hypothalamic amenorrhea compared with the average intensity when their periods were missing. You can clearly see a shift to the right, denoting higher exercise intensity when periods disappeared. With normal periods, the average intensity was between 4-6; when periods were absent, average intensity was more like 6-8.

2. Eating

The second factor is eating. In my case, I started limiting myself to 1500 calories a day, because that’s what my (male) coworkers were doing in an attempt to lose weight. I thought, hey, that should work for me, as a woman I need fewer calories than my guy friends, but I exercise more, so sure, let’s go with 1500.  I made myself an Excel file in which I tracked every morsel that passed my lips, and if I didn’t know the exact number of calories I would overestimate so I didn’t “eat too much.”

Not all our survey respondents tracked how many calories they were eating, but among those who did, my experience was fairly typical. The average consumption when our survey respondents had hypothalamic amenorrhea was 1481 calories a day.

Number of calories eaten per day for women with hypothalamic amenorrhea

This is something that many doctors don’t even ask about when a woman is missing her period. They look at the woman and her physique/BMI, and if she “looks” normal, they don’t dig any further. But many of us are severely restricting the amount of food we eat, mostly in order to maintain/attain the societal idea of thinness.  Never mind the cost.

If we’re not restricting the amount of food, there is often a feeling of wanting to avoid “unhealthy” food, whatever that might mean to you. For some it’s fat, for some carbs, for some cooked food… regardless, the mindset that you have to watch what you eat can cause inadvertent calorie restriction, and also mental stress (see tomorrow’s post!)

Were you exercising more or more intensely when you had hypothalamic amenorrhea than before or afterwards? Did you track and restrict calories, or avoid certain food groups?

Factors in a missing period / no period, part 2


P.S. Feel free to download and share any of the graphs from these posts!