What is hypothalamic amenorrhoea (HA) — and what does nutrition recovery actually involve?
Losing your period gets explained away a lot. Stress. Being busy. Your body adjusting. Give it a few months.
If you're also exercising regularly, eating carefully, or have recently lost weight — even a small amount — there's a good chance the explanation is more specific than that. Hypothalamic amenorrhoea is what happens when the body decides, based on the energy available to it, that reproduction isn't something it can currently support.
It's reversible. But it needs the right kind of support to reverse it.
What hypothalamic amenorrhoea actually is
Hypothalamic amenorrhoea (HA) is the loss of menstrual periods caused by suppression of the hypothalamic-pituitary-ovarian (HPO) axis — the hormonal communication pathway between the brain and the ovaries that governs the menstrual cycle.
The hypothalamus is exquisitely sensitive to energy availability. When it detects that energy intake is insufficient relative to expenditure — that the body doesn't have enough fuel to safely support reproduction — it suppresses the release of gonadotropin-releasing hormone (GnRH). Without GnRH, the pituitary doesn't release LH and FSH. Without those, the ovaries don't produce oestrogen or progesterone. The cycle stops.
This is a protective mechanism, not a failure. The difficulty is that it can be triggered by levels of underfuelling that don't produce other obvious symptoms — and by the time the period stops, the hormonal suppression has often been occurring for some time already.
Who gets hypothalamic amenorrhoea
HA occurs most frequently in:
Women who are underfuelling relative to their activity level — including athletes, women who exercise regularly, and women who eat carefully but not sufficiently for their energy demands
Women with eating disorders or disordered eating, particularly those with restriction or rigid food rules
Women under significant psychological stress, which also suppresses the HPO axis
Women who have recently lost weight — even a small amount, particularly if it occurred rapidly or from an already lean starting point
Importantly, HA does not require a low body weight. Women of all sizes can develop it if their energy intake is insufficient for their physiological needs. This is one of the most common misconceptions about the condition — and one of the reasons it's so frequently missed
"HA does not require a low body weight. Women of all sizes can develop it if their energy intake is insufficient for their physiological needs."
Why HA is so frequently missed
The association of amenorrhoea with low body weight means it often isn't considered in women who appear a 'normal' weight
Women often normalise the loss of their period, particularly if they're exercising heavily or eating 'healthily' — both of which carry cultural approval
Standard blood tests ordered for amenorrhoea may appear within normal range in HA, because the suppression is functional rather than structural
The wellness and fitness culture that often surrounds HA presentations actively validates the behaviours causing it — making it harder for women to see that what they're doing is contributing to a clinical problem
The consequences of untreated HA
HA is not simply a sign that the body needs a rest. Sustained oestrogen deficiency has real
consequences:
Bone density loss — oestrogen is essential for bone maintenance. HA is a leading cause of premature bone loss and stress fractures in young women
Cardiovascular risk — prolonged HA is associated with adverse lipid profiles and increased cardiovascular risk
Fertility — sustained HPO suppression affects egg quality and ovarian reserve over time
Mood and cognition — oestrogen influences serotonin and dopamine pathways; deficiency is associated with depression, anxiety, and cognitive changes
What nutrition recovery for HA involves
The primary treatment for HA is increasing energy availability — eating more, reducing exercise, or both. Simple in principle. Genuinely difficult in practice, particularly for women whose underfuelling is connected to disordered eating or a complicated relationship with food and body.
The work looks different for everyone, but it usually involves some version of the following:
Getting a clear picture of where things actually are. Many women with HA are surprised by the gap between what they think they're eating and what their body actually needs — this isn't a judgment, it's just a starting point.
Working toward enough. Not a number for its own sake, but sufficient energy intake for the HPO axis to feel safe enough to resume function. What that looks like in practice is individual.
Paying attention to fat and carbohydrates specifically. Both matter for hormonal function in ways that go beyond overall calorie intake. Women following very low fat or low carbohydrate approaches — including ketogenic diets — often find these are quietly contributing to the suppression.
Making space for the psychological side of things. For women whose HA is tangled up with disordered eating, eating more isn't just a logistical change — it involves working through the beliefs and patterns that have been running the show for a long time. That part of recovery usually benefits from both a dietitian and a psychologist involved.
Looking honestly at exercise. Where training volume is part of the picture, reducing it is often necessary — and often the hardest ask. Especially for women who have come to rely on exercise for reasons that go well beyond fitness.
If your period has stopped and you're not sure why, that's worth a proper conversation. When you're ready, you can make an enquiry at dietitianannaleise.com/work-with-me.