When was the last time you had a period? If it was more than three months ago (or you’ve recently stopped birth control and not had a period yet), you might have a condition called “hypothalamic amenorrhea" (HA).
This blog post is intended as a definitive guide to hypothalamic amenorrhea, a condition that can significantly impact overall health and well-being. In this post, I will explore what hypothalamic amenorrhea is, its causes, symptoms, and a brief guide to recovery. Whether you’re seeking answers for yourself or otherwise looking to understand this condition better, I aim to provide comprehensive insights and practical advice to help navigate this complex issue.
-Dr. Nicola Sykes PhD, author of “No Period. Now What? A Guide to Regaining Your Cycles and Improving Your Fertility
Definition
Hypothalamic amenorrhea is the absence of a menstrual period because of suppression of the part of your brain that controls reproduction, the hypothalamus.
There are various manifestations of hypothalamic amenorrhea that can include:
no period ever
a regular (or irregular) period that stopped coming
no bleed while on birth control even when a bleed is expected
very long, irregular cycles
When we have hypothalamic amenorrhea, our hypothalamus is suppressed in two ways:
Lack of certain signals (e.g. hormones and chemicals from the breakdown of food)
Excess of other signals (e.g. cortisol from physical and psychosocial stress).
In fact, the hypothalamus regulates and is regulated by various systems through the exchange of hormonal and chemical signals. It is small in size, but large in function! The hypothalamus controls:
Reproduction
Thyroid (metabolism)
Stress
Water retention
Breast milk production
Energy use
Digestion
Each of these systems generates molecules and hormones that are sensed by the hypothalamus and then also controlled by the hypothalamus through feedback loops.
Our brains and bodies are interconnected in so many ways!
The suppressed hypothalamus no longer sends out signals with a normal pattern. In particular, gonadotropin releasing hormone (GnRH) release is negatively impacted.
When it's suppressed from a combination of reduced/insufficient food intake (including of individual macros, and reduced time of eating), high intensity exercise, and possibly stress, a number of systems are affected in order to make the best possible use of available energy.
Reproductive system is slowed or shut down - no period and no libido
Digestive system is slowed
Thyroid function is impacted
This leads to many of the symptoms that are experienced along with a missing period.
Terms
Hypothalamic Amenorrhea is often abbreviated as HA. It is also referred to in many other ways, depending on the context.
Medical:
Functional Hypothalamic Amenorrhea
Hypothalamic Amenorrhea
Hypogonadotropic Hypogonadism
...are all different names for essentially the same condition I have just described.
Sometimes the term "idiopathic" is used together with one of these others; this just means that the cause is unknown. (Note: this is often because medical professionals have not been exposed to the information you will learn here).
Amenorrhea can be described as either primary or secondary.
Primary amenorrhea means you have never had a natural period. This often happens to those who had an eating disorder and/or were competitive athletes as young teens. I have worked with and seen people get their periods after primary amenorrhea at all ages, the oldest being in her late 30's.
Secondary amenorrhea is the term used when you have had natural periods that have subsequently disappeared.
Sports:
Athletic Amenorrhea
Exercise-induced Amenorrhea
Stress-induced Amenorrhea
...describe the lack of a period thought to be due to overexercise (or stress, but often, exercise is considered a form of stress). As you will learn going forward, there is almost always a component of underfueling as well, so these terms are common but somewhat inaccurate.
Female/Male Athlete Triad
Relative Energy Deficiency in Sport (REDS)
...are umbrella terms that include not only the amenorrhea, but also other negative impacts on reproductive and other systems. Note that REDS can be experienced by people of any gender, with obvious differences in reproductive system symptoms, but similarities across the other areas.
Misused terms:
Post-pill amenorrhea (not an evidence-based diagnosis, see more below)
Lean PCOS (HA is often misdiagnosed as PCOS, learn more here)
Hypopituitarism (meaning the pituitary gland is not working; this is rare, HA is more likely)
Factors in hypothalamic amenorrhea:
I have found through my research, personal experience, and experience in working with thousands of people with HA/REDS, that there are five major factors that play a role in hypothalamic suppression.
The five factors are common, but the exact recipe for each person is different.
#1: What you eat
The overriding driver of HA in most cases that I see is underfueling for the body's daily needs.
This can happen in many different ways.
Planned diet for weight loss
Increase in training without increase in fuel
Change in eating pattern
Change in dietary pattern, e.g. moving from omnivore to vegetarian
Lack of access to food
Lack of desire for food
Desire for food not matching needs
Food control, e.g. calorie or macro counting and/or limiting
Medical issue making it hard to get enough fuel
In each case, there is a mismatch between the fuel a body needs to accomplish everything it does day-in, day-out, and the amount of fuel being consumed.
This mismatch causes suppression of the hypothalamus in order to conserve energy.
The most important function of our bodies is to keep us alive, which means energy for breathing, pumping blood, and our brains. Everything else is secondary.
When you underfuel your daily needs, your body has to decide where to use its energy, and reproduction is easy to shut down.
#2: Decrease in Body Size
You can experience hypothalamic amenorrhea NO MATTER YOUR BODY SIZE.
This is really important to understand. The common idea about missing periods is that it happens only to people who are excessively thin and/or elite level athletes.
It is true that people who are on the thinner side, and are elite athletes are more likely to experience HA/REDS.
But! Those are not the only people for whom this can be an issue.
In the survey I did for No Period. Now What? I found that weight loss was much more closely associated with a missing period than absolute body size.
The reason I think of this as a separate factor from underfueling is because.... (and no-one really talks about this!)... body fat is a hormonal organ.
Your body fat generates the hormones leptin and adiponectin, which are sensed by the hypothalamus. Body fat also transforms testosterone into estradiol. So if your hypothalamus is used to one level of these hormones that is then decreased as you lose body fat, that decreased signal can be a suppressive factor.
#3: Exercise
Exercise plays a role in leading to HA/REDS in two major ways.
First - exercise burns energy. So it's a contributor to the underfueling component of HA. Also, lots of people don't know that our body continues to burn additional fuel even after high-intensity exercise is completed, and that can play a role in unintentional underfueling.
Second - exercise increases stress hormones, which suppress the hypothalamus. The intensity of movement is associated with how much your cortisol increases. So the more higher intensity exercise you're doing, the more likely it is to be impacting your system negatively.
It is generally the case that exercise alone will not cause HA. I find that it's almost always the combination of exercise WITH underfueling and/or decreased body size, and possibly psychosocial stress added in as well.
#4: Stress
The role of stress in causing HA/REDS is slightly less well documented, and likely more variable depending on your genetic background.
Acute, intense stress can cause someone to miss a period. Typically only one, unless there are other factors at play. What's interesting is that we all "know" this - but it's not well documented in the medical literature. In fact, I can't find a single research study that describes this phenomenon. (We call this anecdotal data, where it's based on stories not statistics). But it's not uncommon to hear about someone who misses a period right around the unexpected death of a loved one, or after a traumatic event (here is a study that found amenorrhea lasting an average of 2.65 months after spinal cord injury).
Illness, which the body often senses as stress, can also cause a missing period. This has been documented for covid, but I can't easily find research for other illnesses like a cold, flu, or other fever-inducing sickness. So this is also an anecdotal observation.
Chronic stress likely plays a role in how susceptible you are to losing your menstrual cycle, but is rarely a factor of its own accord. One can find research studies that discuss "stress-induced amenorrhea" but they almost always also mention underfueling/overexercise and other forms of stress.
There have been some elegant studies performed in monkeys that find that menstrual cycles are much more likely to be missed with a combination of stress and exercise/underfueling than either with stress alone or underfueling/exercise alone.
Some sources of chronic stress many of us are exposed to can include:
Work stress
Family stress
Financial stress
Medical stress
Food-related stress - counting/measuring food, calories, macros
Body-related stress - weighing, body checking, other measurements
Exercise-related stress - ensuring sufficient steps/getting to the gym/exercising no matter what
#5: Genetics
There are a number of genes that are involved in all aspects of control of the menstrual cycle, from multiple genes involved in the development and migration of the GnRH neurons in the hypothalamus, to the GnRH receptor protein, to other hormones like kisspeptin, leptin, neurokinin B, and their receptors.
This gets complicated but basically, you can imagine a set of interlocking keys and keyholes that control these different systems. If there is a mismatch between a particular key and and its keyhole, then it's more likely that your system will shut down with insufficient nutrition/overexercise/stress or whatever your particular combination is. As genetic testing has improved, mutations (mistakes) in these different keys and keyholes are being found more often, associated with secondary amenorrhea.
There are some people for whom there is such a strong mismatch between a key and keyhole that their system cannot overcome it - this is a place where the term "idiopathic hypogonoadropic hypogonadism" might be most appropriate, although "congenital hypogonadotropic hypogonadism" would be the most accurate term. It would almost certainly be in someone with primary amenorrhea, perhaps related to Kallman syndrome, perhaps with stalled pubertal development.
So essentially, those of us that experience HA/REDS are likely to have some kind of mismatch in our keys/keyholes that makes our system a bit more sensitive than the average person to underfueling/exercise/stress.
Note: This also means that we tend to be more sensitive to suppression by prolactin, the hormone generated when breastmilk is made, so people that have had HA are much less likely than the average person to resume menstrual cycles while breastfeeding/pumping, see Chapter 26 in No Period. Now What?
REVEAL HA Registry
If any/all of this rings true for you, please consider signing up for an ongoing clinical study at the Mayo clinic, that consists of answering survey questions, so that researchers can ask and answer lots more questions about HA! More information in my recent blog post here.
What about post-pill amenorrhea?
This is a whole blog post in and of itself, as there is quite a bit of research to dive into. But the upshot is post-pill amenorrhea is not an evidence-supported medical diagnosis.
It is the case that hormonal birth control - either the birth control pill, ring, injection, patch - will provide your body with some amount of hormone analog, generally either a molecule that your body senses as estradiol or progesterone. These levels are sufficient to activate feedback mechanisms that suppress your follicle stimulating hormone (FSH) and luteinizing hormone (LH) to extremely low levels, such that you do not grow any follicles, do not ovulate, and cannot get pregnant. (Note: less true with the implant and IUD that prevent pregnancy in other ways, it is possible to ovulate with those two methods).
Many of these methods will have you take the hormones in such a combination that you do bleed on a monthly basis. It's important to understand that this is not a bleed because of ovulation, it's a bleed that occurs because of the hormone analogs, so does not tell you anything about the health of your reproductive system.
Anyway - studies have found that a) your gonadotropins will rebound to normal levels during the "placebo" week of the birth control pill, so by 7 days after stopping the pill, and b) that around 90% of people coming off birth control pills will ovulate within a month of stopping, and 95% within 45 days off the pill.
This means that if you have not gotten your period by two months after stopping the pill, there is likely something else going on, and worth investigating.
Many medical professionals are unaware of these data, and were taught in medical school that it is "normal" to take 3, 6, or even 12 months to ovulate after stopping birth control pills. This is incorrect, and I do encourage you to ask for additional testing to try and determine what else might be going on.
Common Symptoms Associated with HA/REDS
In No Period. Now What? we have some graphs of symptoms that people with HA notice, along with the frequency. These symptoms include:
decreased vaginal lubrication
increased urge and frequency of urination
decreased libido
feeling cold all the time
poor digestion (constipation, bloating, excess gas, IBS)
low resting heart rate
difficulty with mood stability
This collection of symptoms is probably better named as Relative Energy Deficiency in Sport, because they are mostly related to the underfueling or possibly overexercise components of the condition; they come along with a missing period rather than being an effect of the missing period.
The symptoms most closely related to the missing period are decreased vaginal lubrication, increased urge and frequency of urination, and decreased libido. These are mostly due to low levels of hormones that do not change through the month as they should.
The most common symptom is feeling cold all the time, and more so than others around you. This is a strong sign that your body is not getting the fuel it needs - it takes energy to keep us warm! One way that the body can save a bit of energy is by dropping your core temperature.
Along with less energy to keep us warm, the body has less energy available for digestion.
When people recommend diets they often fail to note that digestion is a process that requires energy. The entire digestive tract consists of muscles, and muscles need energy to perform properly. Also, it takes energy to make digestive enzymes and hormones. So digestive complaints like constipation, bloating, and excess gas are common with HA/REDS, even to the point of diagnosis of Inflammatory Bowel Syndrome (IBS).
And this becomes a slippery slope because our culture teaches us that when we experience digestive upsets, we should look to the foods we are eating, and often eliminate certain food groups suspected to have negative impacts on digestion. BUT! That almost always means eating less, which actually makes the problem worse.
Another common symptom is a low resting heart rate. We are often pleased with ourselves - we have been led to believe that a low heart rate means we are a strong athlete with a capable heart! However, when the heart rate is low from underfueling, it can be dangerous (a condition called bradycardia, <50 bpm is concerning). In some cases, you can distinguish an “athletic heart” from an underfueled heart by assessing how much your heart rate increases upon standing or walking - if it spikes quickly that is a warning sign; please check in with your physician (but recognize also that many medical professionals are unaware of this symptom of anorexia/underfueling).
Other common symptoms include difficulty with mood/emotion control. This can range from feeling flat and emotionless to being impatient, quick to anger, and anxious. The more our brain is starved of nutrition (our brains use about 20% of the energy we consume each day!), the less able we are to mentally cope with challenges.
(Something else to point out about dieting - we are taught that when we diet we will lose body fat. But we don't only lose body fat. We also lose mass in all these other organs, meaning our body has to work harder to accomplish its normal daily tasks.)
Less common symptoms of hypothalamic amenorrhea
There are lots of other complaints that people might have that one could trace back to undernourishment and lack of normal hormone levels:
Dental issues
Brittle hair/nails
Genital discomfort
Poor athletic performance
Soft tissue injuries
Stress fractures
Poor immune health
"Overtraining syndrome"
You might have all of these symptoms, or you might have just a few. Often the degree of symptoms is related to the degree of underfueling as well as the length of time for which that has been the case.
Downsides of HA
There are both short and long term issues that can arise when someone has HA. It can be easy to brush some of these off, but they can have significant impact on your long term health, so it's generally better to take action now rather than leaving it.... Chapter 7 in NPNW is devoted to the long-term health issues if you want more details.
Dealing with the symptoms I listed above.
Lack of flexibility in your life, being controlled by food and exercise.
Fertility - obviously, you can't get pregnant when you aren't ovulating. Also, fertility treatments tend to work less well (if at all) when you are undernourishing and overexercising.
Bone health - building bone requires both adequate energy and the high levels of estrogen and progesterone that happen around and after ovulation. This can lead to osteoporosis and risks of fractures both before and after menopause.
Brain health - more and more evidence is mounting that a low estrogen state is less good for brains, and obviously, not getting enough energy is detrimental.
Heart health - evidence now shows a lack of elasticity in blood vessels when one has HA/REDS
Upsides of HA
I would be doing you a disservice if I suggested that everything about having HA/REDS is bad. I think it's important to acknowledge the seeming positives, because sometimes we can feel quite good in our bodies with HA/REDS, and it can be hard to let go of that for recovery, where you may very well feel worse for some amount of time.
Especially if you have a painful or heavy period, or have depression or anxiety associated with having a period, not having to deal with those issues can feel quite freeing. And it can also feel scary to think about returning to pain/discomfort/mental challenges of the past.
Also if you have trauma in your history that makes feeling grown in your body challenging, that can lead to discomfort with having a period (I strongly suggest working with a trauma-informed therapist if it's possible for you in this case).
Many of us, especially at the beginning of our underfueling/exercise journey, can feel quite good in our bodies. Performance can improve, we can feel and be stronger, and the high levels of cortisol can keep us feeling jazzed and awake. We often feel like things are just fine, and aren't we doing all the things one is supposed to, to be "healthy"? Not to mention, getting compliments both on outward appearance and dedication to diet/exercise. Many of these physical feelings are short lived and at some point we get to a point of feeling exhausted, sore, drained - but that length of time is different for each person. Its important not to get sucked in (particularly by the compliments) and pay attention to the things that aren't feeling great, the warning bells going off in your head.
HA recovery
The short version is this, called "going ALL IN" in the book:
Fuel your body. I generally recommend around 2500 calories/day (although also doing so without counting routinely because calorie tracking is an added, unnecessary stress).
Eat carbs, fat, proteins, and kick the "diet" foods from your life.
Cut out high intensity exercise (or cut it down, but I find that people are generally more successful with stopping completely for the time being - not forever though!)
Reduce stress where you can - stop counting things, stop weighing yourself, try things like yoga, meditation, mindfulness, look into self-compassion and resilience, be kind to yourself, work on body image, work on accepting everyone (including yourself) for who they are not what they look like, learn about weight bias and fat stigma, curate your social media...
Evidence for all this and many more specific details in No Period. Now What?
Many of the symptoms I described above will decrease by going ALL IN - some in a matter of weeks, some take a bit longer. And going ALL IN can be hard (support groups really help!). But the vast majority of people find the outcome to be well worth the challenge and discomfort.
HA and fertility
The last topic for this definitive guide to HA/REDS is a short discussion of impacts of having HA on fertility.
Obviously you can't get pregnant when you aren't ovulating.
If you were assigned male at birth, it's also the case that REDS can impact sperm generation and quality.
BUT. Once you put in the work on recovery and are ovulating/generating healthy sperm again, there does not seem to be any impact on fertility. People that have had HA/REDS seem to be able to achieve pregnancy at remarkably similar rates to those who have never had missing periods or experienced the negative fertility consequences of REDS.
Our bodies are remarkable
They are able to deal with a monumental amount of things that we throw at them. There may be consequences of underfueling as discussed here, but the thing is - once that underfueling is corrected and your system feels safe again, it is extremely likely that much of the damage will be reversed. In particular, almost everyone who experiences HA is able to restore missing menstrual cycles in a matter of months. Rarely is it a process that takes as long as a year (although it can, depending on your starting point and how quickly you go "all in" on recovery). Rarely do people not recover, and when that happens, either they are unable to stick with the work at the moment, or there is some other issue that was masked by the HA.
The vast majority of people I interact with - both directly as clients, or in my support group, or those I hear from though various social media channels - DO get their periods back, DO reverse other symptoms, DO get pregnant when desired....
There is so much hope for a brighter path forward, as soon as you're ready to take the first steps.
Want to learn more?
Comments