The Science of PMS
When it comes to that time of the month, even you don’t look forward to the seething, angry monster you transform into when your period approaches. Scientists are only now accepting it as a medical reality; or the estimated 3 out of every 4 menstruating women have had some form of PMS in their lifetime, it is most definitely real!
Premenstrual syndrome (PMS) is defined as the wide variety of physical and psychological symptoms that occurs regularly during the premenstrual (luteal) phase of the menstrual cycle, and resolves by the end of menstruation¹.
PMS Symptoms Include a Wide Variety of Signs and Symptoms
Physical signs and symptoms:
- joint or muscle pain
- headache
- fatigue
- weight gain related to fluid retention
- abdominal bloating
- breast tenderness
- acne
- constipation or diarrhoea
- alcohol intolerance
Emotional and behavioural signs and symptoms:
- tension/ anxiety
- mood swings
- irritability or anger
- food cravings and appetite changes
- trouble falling asleep (insomnia)
- social withdrawal
- poor concentration
- change in libido
“Up to 8% of women have a severe, debilitating form of PMS, called premenstrual dysphoric disorder (PMDD).”
While we still don’t know exactly what causes PMS, it has been linked to the following factors:
Cyclical Hormonal Changes
The menstrual cycle is affected by the orchestrated changes in the levels of ovarian estrogen and progesterone. Several body systems, including the cardiovascular system, central nervous system, endocrine system, female reproductive system, and immune system, are replete with estrogen receptors, while progesterone also acts on numerous tissues. Therefore, cyclically fluctuating levels of estrogen and progesterone have a significant physical and emotional effect on the female body.
Chemical Changes in the Brain
Estrogen and progesterone influences serotonin (a brain chemical/ neurotransmitter) levels, which then directly affects mood. A recent study (2023) published in Biological Psychiatry, found that in patients with PMDD in particular, the brain’s response to these changes in the cycle were dysregulated and that the transport of the neurotransmitter serotonin in the brain increases in women with PMDD shortly before menstruation, resulting in the affective symptoms.
Genetic Variations in the Inherited Gene Network
Research has shown cellular evidence of abnormal signalling in cells derived from women with PMDD, which shows a possible biological cause for their abnormal behavioural sensitivity to estrogen and progesterone.
Footnote:
1 Wu, M., Liang, Y., Wang, Q. et al. (2016). Emotion Dysregulation of Women with Premenstrual Syndrome. Scientific Reports. 6:38501 https://doi.org/10.1038/srep3850
References
- Canadian Institutes of Health Research. (2014). Science fact or science fiction: Does PMS exist?. Canadian Institutes of Health Research [Online]. Accessed on 22 March 2023. Available from https://cihr-irsc.gc.ca/e/documents/igh_mythbuster_pms-en.pdf
- Mayo Clinic. (2022). Premenstrual syndrome (PMS). Mayo Clinic [Online]. Accessed on 22 March 2023. Available from https://www.mayoclinic.org/diseases-conditions/premenstrual- syndrome/symptoms-causes/syc-20376780
- Max Plank Gesellschaft. (2023). Not just mood swings but premenstrual depression. MPG [Online]. Accessed on 22 March 2023. Available from https://www.mpg.de/19818475/0127-nepf-not-just- mood-swings-but-premenstrual-depression-serotonin-transporter-in-the-brain-increased-149575-x
- National Health Service. (2021). PMS (premenstrual syndrome). NHS [Online]. Accessed on 22 March 2023. Available from https://www.nhs.uk/conditions/pre-menstrual-syndrome/
- Whiteman, H. (2017). Premenstrual mood changes linked to abnormalities in gene network. Medical News Today [Online]. Accessed on 22 March 2023. Available from https://www.medicalnewstoday.com/articles/315008
- Wu, M., Liang, Y., Wang, Q. et al. (2016). Emotion Dysregulation of Women with Premenstrual Syndrome. Scientific Reports. 6:38501 https://doi.org/10.1038/srep38501