By Dr Yvonne Chow
Endocrinologist
MBBS, BMEDSC, MPH, FRACP
Jean Hailes Clinician

As chemical messengers, hormones facilitate communication between different areas of our bodies. Akin to a natural broadband network it is important that we “listen to our bodies” and what our hormones are trying to tell us.

Sex hormones are particularly prolific in sending us messages throughout our lives from daily oscillations to monthly fluctuations and changes over our lifespan. Sex hormones are notably loud during periods of hormonal transitions such as puberty, pregnancy and menopause. The role sex hormones play in communication is perhaps best illustrated by the menstrual cycle1. Gonadotrophin-releasing hormone GnRH from the hypothalamus stimulates the release of gonadotrophins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary gland. These gonadotrophins encourage the production of oestrogen from follicles and a rise in oestrogen triggers a subsequent LH surge that triggers ovulation. There is a steady increase in the production of progesterone after ovulation by the corpus luteum to prepare the endometrium for possible pregnancy. If there is no pregnancy, then the corpus luteum will regress and the levels of oestrogen and progesterone fall. It is this decline in oestrogen and progesterone levels that lead to the increase in pulses of GnRH from the hypothalamus, thereby beginning the menstrual cycle again.

This chatter by the sex hormones is felt tangibly by many women. Otherwise known as “premenstrual syndrome” (PMS), this is a collection of physical and psychological symptoms that occur in the luteal phase of the menstrual cycle and dissipate with the onset of a menstrual period2. PMS is common, affecting up to half of all women around the world3. Women may experience irritability and bloating and may find benefit from exercise a hot water bottle suffice on the area of abdominal discomfort. At the extreme end of the spectrum, premenstrual dysphoric disorder PMDD is a debilitating psychiatric (DSM-5) and gynaecological disorder (ICD-11) that render around 5% of women unable to participate in their usual daily activities4. These women with PMDD may plan work activities or important events to avoid having them occur in that unpleasant luteal phase, leading up to that menstrual period.

Regular menstrual cycles are also an important indicator of a woman’s underlying health during their reproductive years. Oligomenorrhoea (irregular menstrual periods) or amenorrhoea (the absence of menstrual periods) is not normal and is a symptom that warrants investigation and management. There are a burgeoning number of apps now available for tracking menstrual cycles for women of all ages, which can provide their health professionals with a clearer picture of what the woman is experiencing.  Functional hypothalamic amenorrhoea is an excellent example of the importance of regular menstrual cycles. In the presence of an energy imbalance i.e. more energy is expended relative to food intake, the hypothalamus will switch off the aforementioned GnRH signals5. This results in temporary disruption to ovarian function leading to oligomenorrhoea and often amenorrhoea. Fundamentally this is the body’s desperate plea to slow down – to exercise less and to eat more food.

Changes to the menstrual cycles, often beginning in the fifth decade of life, heralds another hormonal transition – the menopause. This is when the ovaries stop responding to the messages from the gonadotrophins. As a result, there is a marked decline in oestrogen levels which produce a wide array of symptoms6. Hot flushes are most commonly reported but many women will also experience mood changes, vaginal dryness, brain fog, loss of libido and disrupted sleep. Menopausal symptoms usually start a few years before the final menstrual period and will continue beyond the menopause with an average duration of ten years.

By being aware of the symptoms of menopause and the natural course of symptoms, women can better navigate this challenging stage of their lives. There are resources available to assist women and their families in managing the menopause together. Measures may range from wearing light layers to focusing on sleep hygiene. Menopause hormone therapy is also available and the best place to start is to talk to their general practitioner.

References

  1. Reed BG, Carr BR. The Normal Menstrual Cycle and the Control of Ovulation. [Updated 2018 Aug 5]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-.
  2. Freeman EW. Premenstrual syndrome and premenstrual dysphoric disorder: definitions and diagnosis. Psychoneuroendocrinology. (2003) 28 Suppl 3:25–37.
  3. Direkvand-Moghadam A, Sayehmiri K, Delpisheh A, K S. Epidemiology of premenstrual syndrome (PMS)-A systematic review and meta-analysis study. J Clin Diagn Res. (2014) 8:106–9.
  4. Dennerstein L, Lehert P, Heinemann K. Epidemiology of premenstrual symptoms and disorders. Menopause Int. (2012) 18:48–51.
  5. Morrison AE, Fleming S, Levy MJ. A review of the pathophysiology of functional hypothalamic amenorrhoea in women subject to psychological stress, disordered eating, excessive exercise or a combination of these factors. Clin Endocrinol (Oxf). 2021 Aug;95(2):229-238.
  6. Davis SR, Lambrinoudaki I, Lumsden M, Mishra GD, Pal L, Rees M, Santoro N, Simoncini T. Menopause. Nat Rev Dis Primers. 2015 Apr 23;1:15004.