PCOS vs. Hypothalamic Amenorrhea

Is it PCOS or HA?

If you have missing periods, polycystic ovaries that show up in a scan and symptoms like acne or excess body hair growth, you may automatically assume you have PCOS. You may have even been diagnosed by your GP. But there is also another condition which can cause these exact symptoms called hypothalamic amenorrhea (HA). 

There are many similarities between PCOS and HA but there are a few crucial differences that you need to be aware of. And most importantly, the way we treat PCOS and HA at FUTURE WOMAN are very distinct because the causes of each condition are different.

In this article we explore the key diagnostic criteria for PCOS and HA, what the main similarities and differences are between PCOS and HA, and what we recommend to help you regain your cycles.

WHat is PCOS?

PCOS (polycystic ovarian syndrome) is an endocrine-metabolic disorder that affects 4-20% of women worldwide. Those with PCOS often experience missing or irregular periods. Other symptoms of PCOS often include hair loss, excess hair growth on the body, acne and weight gain. 

Read more about the common signs and symptoms of PCOS.

What is the correct way to diagnose PCOS?

It is important to understand how PCOS is diagnosed in the UK to ensure that you had a correct and thorough diagnosis. 

The first and most important thing to note is that PCOS cannot be diagnosed or ruled out by ultrasound alone. This can lead to an over diagnosis of PCOS. Seeing polycystic ovaries on an ultrasound does not mean you have polycystic ovarian syndrome, it can indicate many other things such as Hypothalamic Amenorrhea (HA) or simply young age. 

The medical diagnosis of PCOS in the UK is based on having two of the following criteria (providing that other causes of your symptoms have been ruled out):

  1. Signs of raised androgens (male hormones) either clinically (e.g. acne, facial hair or rarely male pattern baldness) or on blood tests (raised testosterone levels).
  2. Irregular periods or no periods at all.
  3. Polycystic ovaries on an ultrasound scan.

This means that you can technically be diagnosed with PCOS even if you don’t have signs of raised androgen levels. We believe this is misleading since PCOS is always a syndrome of androgen excess, so this should be a mandatory criteria.

As a result, at FUTURE WOMAN we prefer a PCOS diagnosis that meets all three of the following criteria:

  1. Signs of raised androgens (male hormones) either clinically (e.g. acne, facial hair or rarely male pattern baldness) or on blood tests (raised testosterone levels).
  2. Irregular periods or polycystic ovaries on an ultrasound.
  3. Exclusion of any other conditions that would cause high androgens. 

What is hypothalamic amenorrhea (HA)?

Hypothalamic amenorrhoea is a condition that stops your periods due to disruption of the hypothalamic pituitary ovarian axis (HPO). Amenorrhoea is the medical term for the lack of a period.

Symptoms can be very similar to PCOS as they can include missing periods and even acne and hirsutism (body hair growth).

What is THe HPO AXIS?

Essentially the HPO axis is the communication pathway from the brain to the ovaries. The HPO axis is comprised of the following: 

  • Hypothalamus: This is part of the brain responsible for maintaining balance in the body. One of its main roles is connecting the nervous system and endocrine system. 
  • Pituitary gland: Influencing all parts of the body, the pituitary gland has a major role in hormone function by telling other glands to release certain amounts of hormones. 
  • Ovaries: The ovaries are the primary female reproductive organs. They have many important functions including the secretion of hormones and releasing of eggs for possible fertilisation each month.

Hypothalamic amenorrhoea occurs when the hypothalamus, a gland in the brain that regulates many of the body’s processes, slows or stops releasing gonadotropin-releasing hormone (GnRH). GnRH is responsible for a healthy and normal menstrual cycle. 

This hormone stimulates the pituitary gland in the brain to produce follicle stimulating hormone (FSH), the hormone responsible for follicular development in the ovary and causing estrogen production by the ovary. It also stimulates the pituitary gland to produce luteinizing hormone (LH), which helps to mature the egg and triggers the release of the egg for ovulation. 

what causes this HPO axis disruption?

HA is predominantly caused by stress, too much exercise, poor nutrition (usually not consuming enough calories) or a combination of these factors. There may also be a genetic predisposition towards it. Other less common, but well recognised, causes of HA include chronic disease, illnesses that cause malabsorption such as coeliac disease, IBD and hyperthyroidism. 

It is important to note that HA is a reversible condition. 

Let’s have a look more in depth at some of these causes:

  • Stress: Stress causes a lot of hormonal imbalances in the body due to the disruption of the HPO axis. One of these is the release of the hormone corticotropin-releasing hormone (CRH) from the hypothalamus which can decrease the production of GnRH. Chronic stress can therefore suppress the natural pulsatile GnRH secretion which can stop you from ovulating and therefore from having a period. 
  • Poor nutrition or weight change: This can include not getting enough calories in your diet as well as not consuming enough micronutrients and macro-nutrients such as carbohydrates or fats. This is because when your body is deprived of energy and nutrients it starts to save energy by reducing non essential bodily functions such as menstruation. Weight loss or weight gain can also cause HA due to this being an added stress to the body and the hormonal system too. 
  • Exercise: whilst exercise is generally recommended for your health and wellbeing, excessive exercise when the body is already in a low body weight state can be harmful. This again is due to the body having to conserve energy by shutting down non essential functions such as menstruation. In addition, excessive exercise also lowers a hormone called leptin. This is responsible not only for curbing hunger but also regulates GnRH levels by stimulating it. Lower levels of leptin result in lower stimulation levels for GnRH production. 

WHat is the correct way to diagnose HA?

HA is a diagnosis of exclusion. This means that other causes of missed periods need to be ruled out including PCOS. These also include pregnancy, thyroid disease, and a condition where you have too much prolactin (hyperprolactinaemia). 

The GP usually will order blood tests that include:

  • Thyroid function tests: to rule out thyroid disease.
  • Prolactin levels: to rule out raised prolactin.
  • LH and FSH levels: these will be low in HA but LH is likely raised in PCOS
  • Estrogen levels: this is not always done by the GP but can be useful in the diagnosis 

Scans may also be organised and include a pelvic ultrasound looking for polycystic ovaries or any other structural abnormality in the womb that may be causing a missed period.

Although these blood tests hold value there are also other important markers including androgens such as testosterone and DHEA-S that are often not tested by the GP. 

What are the key similarities and differences between pcos and ha?


As summarised in the image above, key similarities include:

  • Absent periods
  • Polycystic ovaries present on a scan
  • Possible acne or hirsutism
  • Low progesterone levels (due to lack of ovulation)

The key differences can only be revealed through hormone testing and include:

  • Androgen levels: With PCOS you will be guaranteed to have high androgen levels, as well as elevated DHEA. In HA it is more likely to have lower androgen levels and low levels of DHEA.
  • LH to FSH ratio: In PCOS LH is typically 3 times higher than FSH. In comparison, you would expect a low ratio of LH to FSH in HA. 
  • Insulin: In over 70% of PCOS cases where insulin resistance is the main driver of PCOS, insulin levels will be high. In comparison, you would expect to see normal to low insulin in HA.

It is worth noting that while estrogen will always be low in HA, we see normal, high or low estrogen with PCOS. 

What do our FUTURE WOMAN tests reveal about PCOS and HA?

In all of our FUTURE WOMAN tests we assess the following:

  • Androgens 
  • DHEA and DHEA-S
  • The 5a pathway (which is typically favoured in those with PCOS) 
  • Estrogen 
  • Progesterone

In PCOS you will expect to find high androgens, high DHEA/DHEA-S, a preference for the 5a pathway and low progesterone. Whereas in HA you will likely find androgens and DHEA/DHEA-S at the lower end, as well as low estrogen and progesterone.  

Read more about testing with PCOS.

The FUTURE WOMAN approach to pcos and ha

At FUTURE WOMAN, we use comprehensive hormone testing and information on your symptoms to create a personalised health plan in order to help you regain your cycles. We usually recommend the Advanced Hormone Test for anyone experiencing symptoms of PCOS or HA, as this looks at not only you reproductive hormones but also your stress hormones which can be elevated with PCOS and HA.

Browse our FUTURE WOMAN hormone tests.

Further help can be offered if you test with us in the form of a 1:1 consultation with a practitioner. This is one of the best ways that we can assess if you may be experiencing HPO axis dysregulation. These consultations allow us to ask specific questions to understand your exact hormonal picture. In these consultations we take into account your hormone test results, we cover everything from thyroid health, adrenal health, ovarian health, metabolic health and more to gain a full picture of what may be going on for you and what may be contributing to missing or irregular periods. 

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