Reviewed By
Dr. June Tan Sheren
Last updated
January 20, 2024

Over 1 billion women globally will be post-menopausal in 2025, yet there is still a stigma around the topic and most women feel unprepared for Menopause. You likely would have heard something at some point about “Menopause” or “Hot flashes” and know that there will come a time when you can no longer have children and your menstrual cycle will cease. But what does it actually mean, when will it start, how long will it last and what type of symptoms should you expect? In this guide we explain the basics of your hormones and the menopause transition; what it is and why it happens. We hope this will  arm you with information you need to make the right decisions for your health and menopause journey.

What is Menopause?

Let’s start with the basic underlying process of what is or will be causing the changes in your body - your hormones and menstrual cycle.

Menstrual cycle 

On a monthly basis a woman’s body goes through what is referred to as a menstrual or ovulation cycle where your ovaries work on releasing an egg for fertilization that can result in pregnancy. This cycle actually consists of two phases (image 1) that are primarily driven by and happen in your ovaries and uterus. 

Follicular Phase - this phase lasts roughly 14 days and starts with your menstruation (bleeding) and ends with ovulation. During this phase your ovaries prepare an egg to be released (ovulation) and estrogen rises to support this process (pink line in image 1). Ovulation has overlap between the two phases, your estrogen levels will peak around this time and drop right after. 

Luteal Phase -  the phase post ovulation is where many women experience premenstrual symptoms due to hormonal changes. Progesterone and estrogen levels rise again and peak roughly midway through the phase to support a potentially fertilized egg. If no fertilization has occurred a few things will happen: 1. Progesterone and Estrogen levels will decrease and your uterus will start breaking down the uterus lining (this is where an egg normally attaches). The following week your cycle will start all over again by cleaning up (shedding) the uterine lining during your menstruation. 

At this point you may be wondering what testosterone (blue line in image 1) has to do with your menstrual cycle. Testosterone is important for a woman’s well being for a few reasons but in this context the most important thing it does regulate your sex drive. The increase of testosterone (and estrogen) around the time ovulation impacts a women’s libido, and to put it plainly, makes you want to have sex at the time your body is prepared for a pregnancy.

Hormones - the basics 

As a woman we have three key hormones that play an active role during our fertile years (and beyond) Estrogen, Progesterone and Testosterone. Hormones are involved in almost every cell and function in our body and keep your body in a delicate balance. When levels start to shift during (peri)menopause, even slightly, we feel it. Having a basic understanding what each of these hormones do will make it easier to understand why Menopause will have a profound physical and emotional impact on the majority of women.


Estrogen is a female hormone released by the ovaries on a monthly cycle, and it’s hugely important in regulating your reproductive health. During early puberty increased production of Estrogen is a key driver for the development of our breasts and our feminine curves. But Estrogen does so much more for the female body - it regulates our metabolic process, bone growth and density, and it is also linked to the part in our brain that controls our emotions. When your Estrogen levels decrease, fluctuate or are in imbalance with other hormones, you may experience symptoms ranging from emotional (depressive thoughts, mood swings) to physical (bloating, UTIs, weight gain). Most women are familiar with some of the symptoms as a by-product of their monthly menstrual cycle. 


Progesterone is the second female hormone and it is also released by the ovaries on a monthly cycle. Progesterone is of critical importance to carry out a pregnancy successfully but it also has a calming and soothing effect on our bodies throughout our lives. Low levels or imbalances in Progesterone can lead to sleep problems, anxiety, panic disorders and irritability. 

Testosterone is important for a woman in a number of different ways; it drives your libido, helps preserve muscle mass and supports an overall sense of wellbeing. The decline in testosterone starts in your 30s and it’s a fairly gradual process that is triggered by age. However, low levels of testosterone can actually contribute to the onset and increase the severity of some menopause related symptoms. 


Menopause stages

Now that we have the basics down and understand how hormones work in our body, let’s move on to the next phase in our lives; Menopause. 

The word Menopause comes from the Greek words 'menos', meaning month, and 'pause', meaning to cease. It refers to the cessation of your monthly ovulation cycle. It’s a single point in time when a woman has not had her period for 12 consecutive months and therefore it’s a (easy!) self-diagnosis made in hindsight. However, often times when speaking about “menopause” what is really meant is the phase leading up to it when symptoms emerge and are often at its worst. This phase, peri-menopause, in simple terms, means around menopause (peri- around).


Women are born with a fixed ovarian reserve (= number of eggs) in their body, and this will eventually run out somewhere in their mid forties. When there are few/ no eggs left to fertilize your ovaries gradually stop working, and the production of the two key female hormones estrogen and progesterone decreases significantly. Progesterone production will decrease first and it tends to be a steep but steady decline. Estrogen will follow a similar steep curve but it will fluctuate a LOT as it decreases (image 3).

Perimenopause can be very unpredictable. Your menstrual cycle will change dramatically - periods can become heavier and (much) more frequent, or the exact opposite can happen where your periods become less severe and your cycle longer. For most women it’s a very confusing time that we are not well prepared for.

Peri-menopause can take anywhere from a year to over a decade to complete. For most of us peri-menopause will start in our mid 40s, but for a significant (3.7%) amount of women it will start as early as their 20s or 30s. Which can be incredibly scary and difficult especially if you are still hoping to have biological children. 

Peri-menopause can be devided into two sub phases:

  • Early peri-menopause: this is where you start experiencing symptoms but your menstrual cycle is still regular. This can be quite confusing and very often women (and their doctors) don’t realise they’ve started their menopause journey.
  • Late peri-menopause: your cycle has become irregular, you may have started skipping periods, and you’ve started experiencing some symptoms. 

Want to speak with a Menopause doctor?

Our doctors specialise in supporting women through menopause, and will get you the help you need.

Symptoms that can be treated

There are 34 symptoms that are frequently associated with the menopause transition. Some are caused by a decrease in absolute levels of a hormone, while others are the result of fluctuating levels or imbalances between the three hormones - Estrogen, Progesterone and Testosterone. 

The rate at which your hormones decrease, the absolute and relative amounts at any time (= fluctuations) and the age at which this starts is different for every woman. While genetics and your medical history may put you at higher risk for certain symptoms, overall the combination and severity of symptoms is unique for every woman and impossible to predict. We have written fact sheets for the most common symptoms going deeper into what the symptom is, why it happens and treatment options. In general there are a couple of key points that you should know:

  • 80-85% of women will experience symptoms that they describe as significant 
  • On average a woman will experience 4 - 5 symptoms
  • Some symptoms are transient meaning they will go away on their own once your hormones settle in Menopause
  • Other symptoms will not get better without treatment such as Osteoporosis, urinary tract symptoms (incl UTIs) and Vaginal dryness.

The eight most common symptoms are listed in the next section. For more detailed information including diagnosis and effective treatment methods please click on the relevant symptom or click here to view all symptoms.

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When does a woman enter menopause

For most of women peri-menopause (the phase leading up to Menopause) will start in her mid 40s, but for a significant (3.7%) amount of women it will start as early as their 20s or 30s. The average for Menopause itself, a single point in time when a woman has not had her period for 12 consecutive months, is 51.

What are the side effect from hormone replacement therapy?

Side effects are normal when starting with any type of hormone therapy (including birth control), and occasionally, women will experience side effects before their symptoms improve. Although there is no definitive data what percentage of women experiences side effects and for how long, the most frequently side effects include: Breast tenderness, Mood changes, Headaches, Spotting or bleeding, Acne and Bloating. Not everyone will experience side effects, but for those who do, they’ll likely subside or dissipate within the first three months of starting treatment. Let your doctor know if any of these side effects persist or are too bothersome.

Long-term risk. Clinical studies have indicated that using certain types of HRT increases your risk of developing breast cancer, heart disease, and stroke. Talk to your doctor about these risks to be sure taking HRT is safe for you.

Read this article if you want to know more about what to expect when starting to take HRT. 

What are the symptoms of Menopause?

There are roughly 34 symptoms of Menopause with the most commonly experienced being:

Medically reviewed and detailed symptom fact sheets can be found here, and a general overview of what (peri) menopause is and entails can be found here.