Your menopause questions answered

What causes the symptoms?
Underlying all the problems associated with menopause are the complex and radical changes that take place in your body's chemistry as your ovaries literally run out of eggs. At birth you have around 450,000 egg follicles, by puberty you have around 100,000, and by your early 40s the loss is even more dramatic. As the eggs run out, the ovaries become less responsive to the hormones designed to stimulate them and produce less oestrogen. At the same time there's a drop in the levels of progesterone - the hormone that thickens the womb lining ready for pregnancy - because no eggs are being released.

‘Menopausal symptoms are almost entirely to do with sensitivity to falling oestrogen levels,' explains Joan Pitkin, consultant obstetrician and gynaecologist at Northwick Park Hospital and Chairman of the British Menopause Society. Oestrogen doesn't just affect the reproductive system - it has an important role in women's general health as well. It affects the bones, joints, blood vessels and heart. It helps govern fat distribution and regulate mood. As oestrogen levels drop the urogenital tract loses tissue, which can cause dryness and itching. Declining supplies of oestrogen to receptors in the cognitive and limbic (mood) centres of the brain can leave you susceptible to moods or experiencing the brain ‘fog' so many women complain of.

Also, when the womb lining is stimulated only by oestrogen - with no progesterone to trigger the shedding that leads to a period - it grows until it outgrows its blood supply and is then shed, causing irregular and often heavy bleeding.

Will it affect me?
It's not clear why some women suffer more than others and for longer. Genes almost certainly play a part in the timing of your menopause, so if your mother/sister/aunt was early or late (the average age is 51) you may be too. Other factors are also important. Smokers usually reach menopause a few years earlier than average, overweight women a few years later. ‘What seems possible is that some women are more sensitive to falling oestrogen levels than others,' explains Joan Pitkin, ‘and one theory is that this is some kind of auto-immune response.' What seems clear is that the more rapidly the body is plunged into menopause, the more severe the symptoms.

What happens during a hot flush?
Dr Bob Freedman, Professor of Psychiatry and Obstetrics and Gynaecology at Wayne State University School of Medicine in Detroit, has spent 20 years studying hot flushes. ‘Although falling oestrogen levels are a primary factor, they're not the only one as we've found similar levels of oestrogen in women who do and do not suffer from flushes,' he says.

He believes oestrogen withdrawal affects the master gland in the brain that controls temperature regulation. Research has shown that levels of a substance in the brain called noradrenaline are higher in women who have hot flushes compared with those who don't. Increased noradrenaline seems to narrow the neutral temperature zone between sweating and shivering - from about 0.4ºC wide, to almost zero - so you become sensitive to slight changes in temperature. The result is that blood vessels dilate, blood flow to the skin is increased, raising your temperature, and your body starts sweating to cool you down.

Should I take HRT?
HRT can banish hot flushes, night sweats and bloating, improve sleep, help with vaginal dryness and reduce irritability. But women have abandoned HRT in droves since researchers in the USA and the UK warned of increased risks of breast cancer, heart disease and stroke.

The UK's Committee on  Safety of Medicines has now recommended that HRT is used only for short term relief of menopausal symptoms and is no longer used as a first line treatment for osteoporosis. But while no one disputes that HRT increases breast cancer risk, many menopause experts say that the risk has been exaggerated - there has already been international criticism of the UK study that found HRT doubled breast cancer risk. Joan Pitkin wants women with menopausal symptoms to be able to make an informed choice about HRT.

‘Unfortunately some GPs are now scared to prescribe HRT so, if necessary, women should ask to be referred to a specialist clinic for advice,' she says. ‘HRT doesn't suit everyone but can do a great deal of good for some women. Not all HRTs are the same - they have different metabolic effects and some will be safer than others for individual women. We can use information about a woman's health and past hormonal background to find the right levels and combinations of hormones. And if women aren't taking HRT it's vital that they take steps to protect their bones.'

The answers to specific problems may not apply to everyone and are not substitutes for professional medical advice. If you're worried, see your GP. For more information, visit www.netdoctor.co.uk<