ARTICLE TWO: UNDERSTANDING THE FOUR PHASES OF THE MENSTRUAL CYCLE & THEIR SYMPTOMS

THE MENSTRUAL SERIES SIMPLIFIED

Author: Janine Soo Thow NZRN/AUSRN & Clinical Preceptor - BSci, BHSci(Nursing), PGCertPHCSpecialtyNursing

A period, also known as menstruation, is a natural part of the female reproductive cycle in which the lining of the uterus is shed through the vagina, typically occurring once a month in women of reproductive age[1].

There are four phases of the menstrual cycle (in the order as follows):

The menses phasethe period. This phase occurs on the first day of your period when the lining of your uterus sheds and flows out of your vagina if a pregnancy hasn’t occurred [1].

Your period is made up of blood, a couple of cells and mucus from the lining of your uterus. The average length of a period is 3 – 8 days.

Hormone levels: low

Symptoms: low energy, mood swings or irritability, physical symptoms such as cramps or mild aches in the lower abdomen, breast tenderness, low back pain, and fatigue. Pain can be very strong on the first two days of your period; however, this can vary from woman to woman in terms of strength and severity. Some women may also experience headaches or tiredness before their period arrives or on their first day[1][2].

© 2025 Mindful & Powerful Within Limited. Illustration by our founder & author, Janine Soo Thow. All Rights Reserved

The follicular phasebegins on the first day of your menstrual period and ends when ovulation begins. The follicular phase is where the Follicle-Stimulating Hormone (FSH) gradually rises and stimulates your ovaries to produce small sacs, known as follicles, that contain undeveloped or immature egg cells to become more mature eggs[2].

The follicular phase can vary from woman to woman but usually lasts from 11 days to 27 days.

In addition to increased FSH levels during this phase, oestrogen levels also rise, causing the lining of the uterus to thicken before a mature egg is released from the ovary into one of the fallopian tubes[3]. The increase in oestrogen can lead to increased energy however, because everyone is different, some people have reported other symptoms during this phase[2][5]. If you have any medical conditions related to hormonal imbalance or take any hormonal birth control, then your symptoms during the follicular phase may be different to what is listed below.

Hormone levels: rise

Symptoms:mood and energy increases – women generally report having more energy, physical symptoms decrease

Ovulation The ovulation phase is when a mature egg is released from an ovary which usually happens once a month. You are most likely to get pregnant/conceive during the time of ovulation if you have unprotected sex[5].

Hormone levels: peak

Symptoms: high energy and confidence, changes in temperature

The luteal phaserefers to the post-ovulation phase. This is where the released egg travels through the fallopian tubes to your uterus. The uterus lining continues to thicken in preparation for pregnancy[3][4]. If you fall pregnant, you won’t have a period. If you don’t get pregnant, you will have a period and the menstrual cycle resumes where the lining of your uterus starts to build up again and thickens to prepare for a possible pregnancy[5].

Hormone levels: drop

Symptoms: bowel movement changes, headache, muscle and joint pain, sadness, mood swings, food cravings, anxiety, bloating, acne or breast tenderness[2].

What to do when you get your period

· Use period products like tampons, pads, menstrual cups or period underwear (whatever you feel comfortable with to help absorb the bleeding).

· Having a period kit ready which can comprise of having some painkillers, period products and a spare pair of underpants in case.

· Track your period by using a period tracker app to record the day your period started and any symptoms that arose

When to see your health practitioner

You should contact your healthcare provider if you have any questions or concerns about your menstrual cycle. Examples of when to contact your healthcare provider are:

· Severe period pain that interferes with your quality of life

· Heavy bleeding

· Bleeding between periods

· Bleeding after sexual intercourse

· Changes in period patterns – for example, your periods come less than 21 days or last more than 8 days

· Irregular or missed periods

· You think you may be pregnant

· Blood clots are larger than a quarter

Please remember, that if you have any of these symptoms above that you find difficult to manage, please seek advice from your healthcare provider or if you require urgent care, please go to the nearest Emergency Department.

Author: Janine is a NZ/AUS registered nurse, clinical preceptor & cervical smear test taker who is deeply passionate about education and sharing knowledge on women’s health, mental health & chronic illness.During her time as a GP nurse & women’s health nurse, she helped run multiple women’s health clinics in Auckland.

Drawing from her professional clinical experiences & personal journey as a patient living with dysmenorrhoea, endometriosis, adenomyosis and PCOS, she firmly believes that knowledge is power and that open discussions of women’s health is essential for advocacy and change.

References

1. The Women’s – the royal women’s hospital Victoria Australia. (2025). About periods. https://www.thewomens.org.au/health-information/periods/periods-overview/about-periods

2. Clearblue. (2025). Menstrual cycles and ovulation. https://nz.clearblue.com/menstrual-cycle/menstrual-cycles-and-ovulation#the-menstrual-cycle

3. Rosen Vollmar, Ana K et al. (2025). The menstrual cycle: a vital sign across the lifespan.The Lancet Obstetrics, Gynaecology, & Women’s Health, Volume 1, Issue 2, e141 - e145. https://www.thelancet.com/journals/lanogw/article/PIIS3050-5038(25)00001-9/fulltext

4. Thiyagarajan DK, Basit H, Jeanmonod R. Physiology, Menstrual Cycle. [Updated 2024 Sep 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK500020/

5. Najmabadi S, Schliep KC, Simonsen SE, Porucznik CA, Egger MJ, Stanford JB. Menstrual bleeding, cycle length, and follicular and luteal phase lengths in women without known subfertility: A pooled analysis of three cohorts. Paediatr Perinat Epidemiol. 2020 May;34(3):318-327. doi: 10.1111/ppe.12644. Epub 2020 Feb 27. PMID: 32104920; PMCID: PMC8495765.