A Comprehensive Guide to the Menstrual Cycle

8 Apr ‘24
8 min
Editorial Board OpenUp
Reviewed by lifestyle expert Rianne Toenhake

Aligned with the natural rhythm of the sun, humans follow a daily cycle known as the ‘circadian rhythm’ or biological clock. This rhythm influences various bodily processes, including body temperature, heart rhythm, and the sleep-wake cycle.


Females* face an extra bio-rhythm in their fertile years: the menstrual cycle. It is one of the main differences between a biological female body and a biological male body*. The menstrual cycle is created by a network of hormones and has a major impact on both emotional and physical well-being.  

* Please note: Throughout our article, the terms ”female” and ”female health” are used. We encourage and welcome individuals of all gender identities to read our article and explore our resources.




The importance of understanding the menstrual cycle


The ebb and flow of hormones wields a profound influence on both emotional well-being and physiological functions. “These hormones affect many bodily functions, ranging from reproductive organs to the brain, heart, skin, thyroid, and even hair. Furthermore, they impact various aspects, including digestion, pain tolerance, creativity, and energy levels,” emphasises Rianne Toenhake, a lifestyle expert at OpenUp and a medical doctor. 


So when you know more about your cycle, you can take better care of yourself and your health. In English, this is defined as body literacy. In other words, it means understanding what your body tells you and applying this information to your life.


Understanding your menstrual cycle provides insights into both your body and emotions. It’s not about being defined by your cycle, but recognising that its hormonal fluctuations can significantly influence your energy levels, mood, and mental well-being. Increased awareness of these influences fosters resilience, encourages self-compassion, and facilitates finding optimal timings for various activities.


How does a menstrual cycle work, and when are which hormones in action? We will dive into that below:

 • The cycle in 2 phases

 • The cycles in 4 phases



The phases of the menstrual cycle (and the hormones at work)


For most individuals, a cycle lasts between 26 and 34 days. You can divide this period in two ways: into two phases or four phases


The cycle in two phases 🎢


Rianne: “Imagine walking up a mountain and, after a nice descent, slowly descending again into the valley. It’s a nice metaphor to illustrate how you can divide the cycle into two phases.”


 • Up the mountain: the period until ovulation (the follicular phase)

 • Down the mountain: the period until the first day of menstruation (the luteal phase)


These two phases are mainly determined by two hormones: follicle-stimulating hormone (FSH) and luteinising hormone (LH). Your hormones are released by a gland just below the brain: the pituitary gland.





Stage 1. The follicular phase (± day 1 to 13)


The follicular phase starts on the first day of menstruation and ends on the day of ovulation. During this phase, the pituitary gland produces the follicle-stimulating hormone, allowing five to 20 eggs to mature in your ovaries. 


The maturing eggs produce the hormone estrogen. One of these eggs becomes dominant and is released at ovulation. The other eggs shrink and are reabsorbed by the body.


To support the maturation of the ‘dominant’ egg, your body produces additional oestrogen. This leads to the thickening of the uterine wall, creating a soft and nourishing environment for a potentially fertilised egg. Increased vaginal discharge is common during this phase of your cycle, facilitating an easier passage for potential sperm from your vagina to your uterus.

Estrogen is the dominant hormone in the first phase of your cycle. It prepares your uterus for nesting an egg. 


You can also notice the dominance of oestrogen in everyday life. You open up more to the outside world, your energy levels rise and you may feel more like being social, planning (work) appointments and exercising. Moreover, oestrogen stimulates the production of serotonin, one of the happiness hormones, which peaks during ovulation. So, chances are high that you feel good, energetic, and confident.



At the end of this phase, your body slowly releases luteinising hormones, oestrogen production decreases, and ovulation occurs. You now enter the second phase of your cycle.



Stage 2. The luteal phase (± day 14 to 28)


Your ovulation or ovulation starts the luteal phase of your cycle, which lasts until the first day of your period. During this phase, the luteinising hormone causes your body to produce more progesterone, the most important hormone in the second half of the cycle.

The hormone progesterone causes the uterine wall to continue growing, preparing the inside of your uterus for a potentially fertilised egg. 

And like oestrogen, progesterone affects how you feel. Emotionally, progesterone makes you turn inward so that you can take care of and protect a potentially fertilised egg. The hormone makes you slow down, making you feel like you want to stay under a blanket. Do you notice this about yourself? Then try to be mindful of it and take more time for yourself during this phase – if your schedule allows.

During ovulation (or ovulation), the matured egg is released by the ovary. The egg finds its way to the fallopian tube, which is not attached to the ovary. The egg has to make a small jump, so to speak, to enter the fallopian tube, hence the word ovulation. 


From the fallopian tube, the egg finds its way to the uterus. If a sperm is present there, the egg can be fertilised. Meanwhile, the uterine wall is completely ready to receive the fertilised egg.

If the egg is fertilised, it looks for a place to implant. But if fertilisation does not occur, the hormone progesterone drops and the extra lining of the uterine wall comes off: you bleed. You experience this as your period. With this, the second phase ends, and your cycle starts again.



The cycle in four phases 🍂


We have now seen that the menstrual cycle is defined by two distinct moments: menstruation and ovulation. But you could also think of the time between those moments as separate phases. Thus, the cycle breaks down into 4 phases, which can help you understand a woman’s body even better.  

You can also think of the menstrual cycle as the four seasons of the year:

 • Winter: menstruation (4 to 7 days long)

 • Spring: the phase before ovulation (10 to 14 days long)

 • Summer: the period around ovulation (3 to 4 days long)

 • Autumn: the phase after ovulation until menstruation (10 to 14 days long)




💡 It is good to know that these stages are a general picture. How they proceed and how long they last is different for everyone. After all, every woman’s body is different, and each woman’s personal experience* is unique and valid. The course of the cycle can also change at different times in your life.



1. Winter (lasts 3 to 7 days)


During menstruation, your body needs rest. So try to give in to that and, if you can, consciously keep your schedule empty. Stay at home more often, choose less intensive sports (such as yoga or walking) and do things that give you peace: do a mindfulness exercise, read a book, paint, write.

What is a 'normal' menstrual cycle?

Every individual’s body is different, but some signals indicate whether the menstrual and hormonal cycle* are balanced: 

 •  Blood loss is such that a tampon or sanitary towel can stay in place for at least 2 hours (a cup longer). 

 •  Abdominal pain should be nothing more than an occasional cramp or feeling of tightness in the lower abdomen. You don’t need painkillers. 

 •  Breast pain is no more than a feeling of ‘fullness’. It does not include breast pain, cysts or cyclical lumps.

 •  Headaches and/or migraines do not accompany a normal cycle. 

 •  Mild changes in your mood and emotions: see the heading ‘PMS’ below.


Consult with a doctor, preferably your GP, if you experience symptoms such as heavy bleeding (requiring a change of tampon or pad every 2 hours), bleeding persisting for more than 7 consecutive days, heightened severity of pain compared to your usual experience, or increased pain either outside your regular period or if the pain intensifies. Following NHS advice, and seeking medical guidance is important in these situations.

Want to learn more? Take our course on The Fundamentals of Menstrual Health 


2. Spring (lasts 10 to 14 days)


Following menstruation, when the body produces more oestrogen, many individuals experience an increased desire to engage socially. This surge in energy makes it easier to connect with the outside world.


During this phase, you may find yourself brimming with ideas and inspiration. It’s an opportune time for socialising, meeting new people, going on dates, scheduling work appointments or presentations, brainstorming, and embracing new experiences.



3. Summer (lasts 3 to 4 days)


During ovulation, when progesterone levels rise, you experience a peak in physical strength. A lengthy to-do list doesn’t faze you, and you effortlessly tackle substantial workloads. It’s an ideal period to schedule significant tasks. Additionally, you may observe an increased capacity for caring for others. In summary, during this phase, you feel positive about yourself and ready to take on the world.



4. Autumn (lasts 10 to 14 days)


When ovulation has occurred, some women find that they become more emotional or insecure more quickly. Because of the drop in oestrogen, you may be more susceptible to your inner critic (we all know it). 

You might notice an increase in temperament during this phase—feeling more fiery, irritable, or less inclined to engage in activities. This could be indicative of a slight dip in energy levels. Consequently, the ‘autumn’ of your cycle is an opportune moment to ease up. Pay attention to your intuition and reflect on the preceding two active phases. It’s a favourable time for introspection and rest.


Many individuals feel less strong or at ease physically and/or mentally after ovulation or just before menstruation. You may experience bloating or sore breasts or notice mood swings, irritability or low energy.

Does it hinder you in your daily life? Then, you might have premenstrual syndrome (PMS). About five per cent of women aged between 15 and 45 experience PMS


There isn’t a specific laboratory test to diagnose PMS. Nevertheless, you can maintain a straightforward diary by recording your daily experiences on physical, mental, emotional, and social levels throughout your cycle. Mild mood swings, like a reduced appetite for socialising, lower energy levels, slightly restless sleep, and increased cravings, are considered normal. However, if your mood changes are extreme or make you feel out of control, it’s advisable to consult your GP.

The importance of tracking your menstrual cycle


Your cycle has a significant impact on the functioning of your body. The rise and fall of hormones changes certain bodily functions, as well as your energy level, mood and emotional and mental well-being.


So, the menstrual cycle is an important gauge of overall health. This is why knowledge about it is so important.


To better understand and control your body, consider tracking your menstrual cycle. Whether using a diary, calendar, online tools, or an app, the method matters less than the act of recording. As advised by Dr Rianne Toenhake, document details such as the heaviness of your period regarding blood loss and pay attention to various physical and emotional signals throughout different phases of your cycle.


This way, first of all, you are aware of how you feel daily and can live more in tune with your body and mind. But above all, you keep track of how your body functions with time. “Do you notice something ‘different from usual’ about your body or how you feel mentally? Then you can take that diary to your GP or gynaecologist,” Rianne says.


💡 Want to know more about the hormonal cycle and how to support it with a healthy lifestyle? Follow our (free) online course to learn all about your menstrual cycle


Our blog is backed by extensive research from multiple medical sources, although not all are cited here. The OpenUp editorial team and lifestyle experts have conducted thorough research; please feel free to contact us for more information on the additional references.

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