Image: Samantha Jones experienced menopause in Sex and the City 2.

Even if you’ve never experienced menopause first-hand, you’re probably familiar with what it is and how it can affect your body.

You probably also assume you won’t have to think too much about it until you’re approaching 50. However, that’s not necessarily the case. The hormonal changes that precede menopause can affect women as early as in their late thirties, and the effects can be equally significant and long-lasting.

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This transitioning stage is known as perimenopause, and it generally takes place over a period of four to six years, starting around age 45— although this changes from one woman to the next.

Perimenopause is caused by changing hormone levels in the body, particularly oestrogen, due to the ovaries beginning to run out of eggs. For the majority of women, ovulation doesn’t suddenly stop — this winding-down process can begin years before menopause. However, around eight per cent of women have menopause induced through surgical removal of the ovaries or as a result of cancer treatment.

According to Dr Mandy Deeks, Head of Translation, Education & Communication at Jean Hailes for Women’s Health, many women aren't familiar with perimenopause because of the way we define menopause itself.

"There's a lot of discussion about 'the menopausal woman' who's in her 50s with the hot flushes ... Women talk about menopause as it relates to mid-life a lot of the time, but we know it doesn't always occur in mid-life," Dr Deeks says.

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"No-one really thinks about what happens before. Menopause is defined as it's been 12 months since your final menstrual period ... and therefore you don't know you've been through menopause until it's been 12 months."

A characteristic symptom of perimenopause is changes to your period pattern. Your cycle can become irregular, more painful, lighter or heavier, and periods might last longer or finish earlier than you're used to. (Post continues after gallery.)

However, perimenopause is also associated with the gradual onset of menopause symptoms, which can include fatigue, hot flashes, breast tenderness, vaginal dryness (try Verona Intimate Fresh Daily Wash or Sensitive Daily Wash, $9.95), headaches, mood swings, incontinence and trouble sleeping. It can also cause women to experience difficulty conceiving and a decreased libido; research indicates up to 15 per cent of perimenopausal women report having no sexual desire.

As with almost anything, no two women experience menopause or perimenopause the same way. You might not even realise you've been through perimenopause because the symptoms haven't been obvious until you consider them in hindsight.

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"It might be that a woman has an early or a premature menopause, or it might be through surgery. It might be that suddenly she wakes up and realises, 'I haven't had a period in a long time' and she hadn't had any symptoms that would tell her she was heading to menopause. Another women might suffer extreme hot flushes, night sweats, that kind of thing," Dr Deeks says.

There is currently no test for perimenopause. However, considering whether you've had changes in your period cycle, and whether you're experiencing any of the menopause symptoms mentioned above, can help you identify it.

How you go about managing perimenopause is largely determined by your individual experience and what works for you.

For example, if a woman experiences heavy bleeding, she may be advised to have an IUD inserted, while Hormone Replacement Therapy (HRT) can provide relief for numerous side-effects, including hot flushes, mood swings and vaginal dryness. Of course, it's important to discuss your options with a GP before undertaking any treatments.

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More generally, a healthy diet and regular exercise can help to relieve the symptoms of perimenopause, particularly those related to mood, fatigue and stress. Some women also find breathing and relaxation techniques help with managing hot flushes.

Hot flushes? Water will help cool you down. (Post continues after gallery.)

"If you notice a change to how you have usually been in your physical or even your emotional health, and it starts to worry you, go to seek help. It could be menopause, but there are other reasons to have menopause-like symptoms like hot flushes and things like that. and that requires investigation," Dr Deeks says.

If you want to do some research before making an appointment so you can come armed with questions, Dr Deeks recommends visiting reputable websites with evidence-based information, such as Jean Hailes for Women's Health.

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"The thing with menopause is it happens at a time in your life when the rest of your life is going on. You might be in a new relationship , or you might have new friends or a new role," she adds.

"It's about looking at your life, what else is going on in your life at this time, and how are you in terms of your physical health as well as menopause."

Have you ever been through perimenopause? What was your experience like?

For more information, our sister website Debrief Daily has produced an episode of their 'Just Between Us' podcast that's all about perimenopause. You can listen and subscribe on iTunes here, or by clicking the SoundCloud link below.

But a warning – this podcast contains a singing ovary, fallopian tubes and clitoris. Their song is so catchy you might find yourself singing it at work and in the train, and that’s not really that appropriate.