PCOS or Hypothalamic Amenorrhea?

According to the Rotterdam diagnostic criteria for PCOS, you have to have 2 out of 3 of:

  • irregular or anovulatory menstrual cycles
  •  polycystic ovaries on ultrasound (not the same as an ovarian cyst)
  •  manifestations of androgen excess or high levels of androgen(s) on bloodwork

And these symptoms should not be arising from another health condition like adrenal hyperplasia or hyperprolactinaemia etc. There was a time (just a few years ago actually) where I would get PCOS patients who had not yet been diagnosed with PCOS. Now, however, I actually get a fair few patients who are misdiagnosed as PCOS.


white square with a red horizontal streak in the middle. On the streak is the acronym PCOS in white, underneat the word misdiagnosed in black

The main differential diagnosis in this case ends up being hypothalamic amenorrhea (HA). This is when the lack of menstruation is arising from more of a stress response due to psychological or physiological, or both types of stress.

The most common types of physiological stress usually stems from a lack of appropriate fuelling for e.g. eating too little or exercising too much (while not eating enough).

In HA, you may see a lot of similarities to PCOS:

  • lack of ovulation and/or irregular cycles
  • polycystic ovaries on ultrasound
  • symptoms similar to those of hyperandrogenism like hair loss and acne
  • mood and energy issues
  • vitamin D deficiency

But, we don’t see other metabolic dysfunction commonly seen in PCOS (like insulin resistance) in HA. Without a thorough investigation around your medical history, lifestyle, food, nutrition, and testing, these two conditions can definitely be confused with one another, and consequently there could be a completely ineffective (and also inappropriate) treatment plan in place if we end up barking up the wrong tree. We can’t only rely on ultrasound or menstrual symptoms — we have to marry bloodwork, imaging, menstrual symptoms, and everything else mentioned above to get a full picture of what’s going on so you can be supported appropriately.