IT'S an inevitable part of life for a woman, but what's really happening with those hot flushes, joint aches and mood swings? We break down those menopause mysteries...

It's a well-known saying only two things in life are certain - death and taxes - but for women, there's menopause too.

We know it will strike eventually, most often when you hit your late 40s and early 50s. But despite the fact it's such a common part of life, menopause remains a bit of a mystery and is something many women don't totally understand.

As well as the promised hot flushes, mood swings and the end of popping to Boots for sanitary products, there's more going on beneath the surface, and how it affects one woman to the next can vary dramatically. Some claim they actually feel better during and after menopause, while for others it can have a big impact on their health and well-being.

Here's the low-down - from the experts - on what's happening to you.

* Aching joints and back pain. Oestrogen levels fluctuate during menopause. The hormone usually gives strength to muscles and ligaments, so without it, your joints can get achy and are more susceptible to injury. To combat the effects, try to do Pilates at least twice a week, says Lynn Robinson, founder of Body Control Pilates. "Unlike other sports and exercises, Pilates is done in safe and supportive positions to cut out the risk of strain on joints."

* Brittle bones. "During and after menopause, when oestrogen levels are low, the process of bone loss starts to speed up and can lead to osteoporosis," explains nutritionist Michela Vagnini. Eat healthily, exercise and supplement your diet with vitamins to boost your system. This will make sure the collagen, calcium phosphate and calcium carbonate in your bones (substances woven into them for strength) remain topped up and active.

* Excessive sweating and hot flushes. Almost 75per cent of women will experience hot flushes during the menopause, and the NHS recommends avoiding certain triggers such as woolly jumpers, stress, alcohol, coffee and spicy foods. Always carry a bottle of water to help keep you cool.

* Thinning hair. Perhaps the most dreaded side effect of menopause is hair loss. "When the levels of female hormones drop, the effects of androgens (male hormones) can increase, causing hair to fall out," says Shona Wilkinson, head nutritionist at nutricentre.com. "Another primary cause of hair loss in women is low levels of iron." Speak to your doctor and make sure there's enough iron in your diet.

* Weight gain. You may have to learn to love your 'spare tyre'. "If you are going into the menopause, your body will be extremely reluctant to let go of the fat around your middle," explains Marilyn Glenville, author of The Natural Solutions To Menopause. "This is because fat is a manufacturing plant for oestrogen, which will help protect your bones from osteoporosis. It's a very clever system, designed to protect you, but it helps explain why diet and exercise alone will rarely shift that stubborn fat."

* Bloating and constipation. Unstable levels of oestrogen can wreak havoc on your gut too, causing excess wind, constipation and bloating, says Adrienne Benjamin, nutritionist at ProVen Probiotics. It leads to less bile being produced, meaning the gut is drier than usual, creating the perfect environment for the above conditions. Stock up on yoghurt to promote friendly bacteria in the gut to relieve symptoms.

* Dry skin. "Skin regenerates itself every two to four weeks when we are younger, but takes between six and seven weeks as we get older. Low levels of oestrogen mean slower production of skin-smoothing collagen and oils, as well as reduced ability to retain moisture," explains Dr Glenville. This can also affect lubrication during sex. It pays to be strict with your moisturising regime and invest in a good lubricant.

* Mood swings. Low oestrogen can reduce levels of the 'happy hormone' serotonin in your system. Combined with sleep deprivation (thanks to night sweats) and you've got the perfect recipe for mood swings. A good night's sleep and a diet rich in Omega-3 fatty acids should get you back on an even keel.

* Weak bladder. "The drop in oestrogen after the menopause causes the bladder muscles to lose their strength and flexibility," explains Dr Glenville. So get practising your pelvic floor exercises and work those muscles!

* Low confidence. All of the above can lead to low self-esteem and a desire to crawl into a ball and hide until it's over. The thing is, 50% of the population will experience the menopause, so don't be afraid to talk about what you're going through. Share horror stories, worries, fears and tips for getting through it. And if in doubt, always speak to your doctor.