The difference between perimenopause and menopause – and how to tell which one you’re in

Pre-menopause is when you have no symptoms of either perimenopause or menopause. This is also referred to as the reproductive years, when the menstrual cycle is active. Periods may be regular or irregular, but they are still happening.  

Although you may experience hormone fluctuations or changes during this time, they don’t tend to result in any noticeable changes in your body. 

Perimenopause can start quite a long time before menopause. How long it lasts and when exactly it occurs is unique to each person going through it, but as a general rule, it begins around mid-forties and lasts for five to seven years.  

It’s at this point in our lives that the menstrual cycle may become irregular. You may notice other symptoms too, such as mood swings, difficulty sleeping, or the beginnings of hot flushes.  

All these are caused by oestrogen levels beginning to decline, and they will continue to drop (unless hormone replacement therapy is used) right up to menopause. During this time – and don’t forget, this is over a number of years – symptoms may come and go, get worse or better, and change.  

Again, this is unique to everyone. Some people experiencing perimenopause have few symptoms while others have many. Some have one issue that is difficult to deal with, or they may have multiple minor issues. There is no hard and fast rule.  

The biggest change taking place during perimenopause is with the menstrual cycle. Dr Sarah Hillman is a women’s health expert and associate professor in general practice at the University of Warwick. She explains that it can vary throughout this time:  

“There’s early phases of perimenopause when your periods or cycles can be quite variable, and then there’s a later part when you start missing the odd period. You have symptoms because of oestrogen levels going down throughout that time. Finally, you get to the stage where you have your last period, but until you’ve gone 12 months [without a period], we can’t say you’re definitely menopausal.” 

We’ve established that perimenopause begins when oestrogen levels begin to decline, but it’s a tricky thing to formally diagnose, as Hillman explains:  

“People are only just becoming more aware of their symptoms in the perimenopause,” she says. “But that early stage of perimenopause is really hard to diagnose, and until you start going through the later stages and you’re missing periods, it’s really tricky.  

“It’s dependent on your age as well. If a woman comes to see me, it depends on how old they are as to whether I’ll say this is a perimenopause or menopause and we need to investigate this further. If you go through the menopause under the age of 40, you’ve actually had something called premature ovarian insufficiency, and that needs further looking into. And then between the ages of 40 and 45, if you go through the menopause, then you’re going through an early menopause. Anything over the age of 45 is classed as a normal time.” 

Early symptoms of perimenopause may be barely noticeable. Some women may experience spotting or irregular bleeding in the middle of their cycle (and if concerned should seek advice from their GP), other women may feel more tired than usual, or as if they can’t do everything they used to do.  

Of course, that’s tricky in itself, because the age at which these changes begin to occur (usually in your forties) coincides with a time in your life when you’re also likely to be busier than ever; working, raising teenagers or young adults, possibly caring for parents or elderly relatives, running a household, and so on. It’s easy to dismiss tiredness or a lack of energy as ‘one of those things’, but it may be the beginning of perimenopause.  

As you move through this time, symptoms become more noticeable and wide-ranging. They include – but are not limited to – the following recognised symptoms:  

Physical symptoms 

• Hot flushes 
• Night sweats 
• Vaginal dryness 
• Incontinence 
• Urinary tract infections 
• Aching joints 
• Breast tenderness 
• Weight gain (especially around the middle) 
• Bloating 
• Digestive issues (including constipation or diarrhoea) 
• Dry skin 
• Heart palpitations (fluttering) 
• Headaches/ migraines 

Psychological symptoms 

• Irritability 
• Forgetfulness  
• Brain fog 
• Depression 
• Anxiety 
• Tiredness/ fatigue 
• Confidence issues 
• Sleep issues 
• Loss of libido 

Menopause is technically when it has been one year and a day since a woman’s last period.

Menopause occurs when oestrogen levels drop to a point where your ovaries no longer release eggs, and so the menstrual cycle comes to an end. 

Oestrogen is a fundamental hormone for everyone – male and female. It’s present in every cell and underpins many physiological functions. Because it’s one of the primary female sex hormones in women, when it declines, we notice the effects.

If you’re considered in the normal age range for menopause (45 onwards), you’re unlikely to need a formal diagnosis because it’s physically noticeable (by periods stopping and other symptoms). However, it can be diagnosed by looking at the follicle stimulating hormone levels (FSH), as Hillman explains:  

“The average age of menopause is 51. We classify anything from 45 onwards as being in the normal time range. And the important thing about that is if you go to your doctor and say you’re experiencing these symptoms, there is no reason really to do any further investigations like blood tests, to gauge follicle stimulating hormone levels. 

“FSH comes from your brain, and it fires it down in your ovaries to make you ovulate. When you’ve gone through the menopause, that level goes up because it’s firing, saying ‘come on, ovulate, ovulate,’, but there’s nothing there to ovulate. So, when that level is high, we know people have gone through the menopause, but before then (in perimenopause) the level can be all over the place. But if you’re aged 45 and over, [and you have symptoms of menopause] we would just say you’re going through menopause.” 

The biggest sign you’ve gone through menopause is no more periods.

However, it may not be as simple as that if you’re taking any form of contraception which may also act as a hormone replacement, such as the combined pill, Mirena coil, progestogen-only pill (POP or mini-pill), or others.

These may alter your menstrual cycle, regardless of whether you’re menopausal. Some women have no periods while taking these, while others have light or intermittent periods.

Some contraception will be suitable for taking throughout the menopause transition as a form of hormone replacement therapy – your GP, sexual health nurse or menopause specialist can advise you on this.  

If your menstrual cycle is being altered by hormone-based contraceptives, you may or may not know whether you’re in the later stages of perimenopause or menopause, based on your age, whether or not your contraceptives are effectively replacing your natural hormones, and if you’re experiencing any of the symptoms listed above.

As you move into the later stages of perimenopause, the symptoms listed above may become more common.

Once in menopause – so, a year past your last period – symptoms may continue for around another four to five years, but they will subside in intensity and frequency. Of course, this being menopause, it’s unique to each individual. Some women report their symptoms last longer than this.  

There are various treatment options available for menopause symptoms. Options include HRT, cognitive behavioural therapy (CBT), and complementary or alternative therapies. Treatment is also available for specific menopause symptoms, such as oestrogen cream for vaginal dryness.

Again, it’s an individual thing. Some options may not be suitable for some people. Some have great experiences with one form of treatment, others don’t. It comes down to suitability and personal choice.  

It’s therefore a good idea to book an appointment with your GP or a menopause specialist to discuss your symptoms in more detail.  

Whatever stage you’re at in the menopause transition, it can be a good idea to have an honest and open menopause discussion with loved ones, too. Being able to talk about symptoms and how you’re feeling can help make menopause a more positive experience.