* The menopause occurs when a woman's ovaries stop producing hormones and mature eggs capable of fertilisation
* The average age for it to happen is about 51, although some women experience a premature menopause before they turn 40
* Hot flushes and night sweats are the most common symptoms, affecting up to 85 per cent of post-menopausal women. Symptoms usually last between one and three years
* No one really knows why hot flushes happen
* The male 'menopause' is known as the andropause, although men don't suffer a sudden drop in their male hormones
Almost a quarter of teachers are women aged between 45 and 54. The average age of menopause is 51, so most staffrooms - especially in primary schools - will include menopausal women. And often they are women at the top of their career ladders: headteachers, heads of department, long-serving classroom teachers. Yet it is amazing how little the menopause is acknowledged. It is, as Diana Laffin says, a staffroom taboo (see case study). There is no doubt that the menopause can have huge physical and psychological consequences, which are not made any easier by the reluctance to talk about them. This is in contrast to many women happily admitting to it being "the wrong time of the month" or telling countless tales of their experiences of childbirth, even years after the event. But there is a strange silence around menopause.
What is it?
The menopause happens when the ovaries stop functioning as an endocrine gland. The ovarian follicles which contain the female eggs and produce the sex hormones oestrogen and progesterone simply die off.
There is no defining "time", but women are considered to have reached the menopause and be post-menopausal when menstruation has stopped completely for a year. By this stage there are insignificant hormone secretions from the ovaries that are devoid of follicles.
The average age of the menopause is about 51, ranging from 45 to 55, although some women experience a premature menopause before they turn 40.
No one knows why this apparently programmed cell death in the ovary happens or, in fact, why the loss of female hormones from the ovaries causes some of the more common menopausal symptoms.
The post-menopausal woman is oestrogen-deficient, and it is this which causes problems. But she is not completely devoid of oestrogens because the adrenal glands that produce the stress hormone, cortisol, also produce androgens. These can be converted to oestrogens in tissues such as the breast, skin, brain and urogenital tract.
What are the most frequent symptoms?
Hot flushes and night sweats affect between 35 to 50 per cent of peri-menopausal women (the years leading up to menopause) and up to 85 per cent of post-menopausal women. Vaginal dryness, which affects about 17 to 30 per cent of women, happens because the vagina shrinks, the vaginal skin thickens and its secretions diminish with the fall in oestrogen. Sex often becomes uncomfortable or painful. The neck of the bladder and the urethra undergo similar changes, which can lead to more frequent urination and to stress-induced incontinence. Such urinary complaints arise in about 15 to 36 per cent of women. Other common symptoms include sleep disturbances (35 to 60 per cent of post-menopausal women) and mood swings (8 to 38 per cent).
The menopause is often associated with psychological problems such as depression, poor memory, poor concentration, tearfulness, anxiety and loss of interest in sex. It is not clear whether these symptoms are a result of oestrogen deficiency per se, or a reaction to physical symptoms such as the loss of sleep associated with night sweats. There's no doubt that most women suffer from some of these symptoms, but hot flushes and night sweats predominate. Generally, menopausal symptoms last between one and three years, sometimes longer.
What causes hot flushes and night sweats?
No one really knows, particularly because the flushes and sweats are spasmodic and the oestrogen decline is permanent. One theory is that oestrogen withdrawal makes the brain more sensitive to a chemical that transmits signals from one neurone to another. So, when any external or internal signal such as coffee, alcohol or stress stimulates the release of this chemical (serotonin), the brain reacts more strongly. As a result, the set point of our thermostat in the brain destabilises and our nervous system initiates reactions to cool down our body. These include increasing blood flow in the skin - hence the flushes - and sweating. Hot flushes (known as flashes in the US) and night sweats are the most common reasons why women seek hormone replacement therapy (HRT). More than 80 per cent of women who opt for this therapy find relief from their symptoms.
What is HRT?
There are several options; it depends whether a woman still has a womb and whether she finds continued menstruation acceptable. Two of the oldest and still most widely used preparations are Premarin and Premique. The first contains conjugated oestrogens extracted from the urine of pregnant mares and is given to women who have had a hysterectomy. The second contains the same oestrogens, plus a synthetic progestagen. This combination prevents the lining of the womb from building up and putting women at risk of endometrial cancer.
Of these combined preparations women can choose to take a daily low dose of both hormones to avoid menstruation or take the "cycle" therapy to mimic the changes of hormone secretions that occur in the natural menstrual cycle. Regular menstruation will occur. Other low-dose combinations contain synthetic oestradiol and a progestagen, and tibolone, also known as Livial, which is a synthetic steroid containing oestrogen, progestagen and androgen. The androgenic component enhances libido.
The important point is that you can change the type of HRT if your first choice (or your doctor's) has side-effects such as bloating, weight gain and menstruation. You also need to remember that HRT may simply delay menopausal symptoms. Most women experience some symptoms when they stop HRT; hot flushes and urogenital complaints are the most common, although the latter can be treated with topical oestrogen.
Is HRT safe?
Two recent studies (the Women's Health Initiative and the Million Women Study) showed that HRT increases the risk of breast cancer and venous thrombosis, particularly after four or more years of use and with a combination of oestrogen plus a progestagen rather than oestrogen alone.
They also showed that HRT offers no protection against cardiovascular disease. While these studies have their limitations, the media is always eager to capitalise on any controversial medical topic and reported on the relative risk of taking HRT rather than absolute risk. The WHI study showed a 26 per cent increase in the relative risk of developing breast cancer, which sounds high but in real terms means that among 1,000 women taking HRT there would be about four cases of breast cancer diagnosed each year compared with an average of three cases in women not taking HRT. Similar figures for the relative risk of coronary heart disease and stroke were between 20 and 30 per cent.
To counterbalance this, you need to weigh up the positive consequences such as a reduced risk of osteoporosis and colon cancer. The relative benefit of HRT on hip fractures was 34 per cent which, in absolute terms, means two fewer hip fractures per 1,000 women taking HRT compared with those not taking HRT. A 37 per cent decrease in colon cancer was also reported. As a result of these and other studies, current guidelines are that HRT should only be prescribed for a short period (up to two years), simply to treat acute menopausal symptoms.
In the late Sixties and early Seventies, HRT was promoted as a sort of elixir for life, protecting against loss of sexual desire, wrinkly skin, bowed back (Dowager's hump), broken bones and other long-term symptoms of oestrogen deficiency. All physical signs of ageing could be offset by HRT and thus women could stay feminine forever! Few people today would support this view of HRT, least of all as an essential prop for prolonged femininity.
Are there alternatives?
Media hype arising from these studies put both women and the medical profession on alert; the outcome was a reduced use of conventional HRT and an increase in the uptake of natural alternatives. These include extracts of soy, of red clover and of the roots of black cohosh. The first two have a weak oestrogen-like action, but their effects on alleviating hot flushes are at best minimal. In fact, most controlled studies have shown that any improvement in symptoms is no better than receiving a placebo pill that contains no active ingredients. Black cohosh may have a mild effect on hot flushes, but it is not known how these extracts work.
What are the long-term consequences of oestrogen deprivation?
The biggest problem is osteoporosis, when bones become thinner and much more prone to fracture, particularly in the wrists, hips and spine. There is no doubt that osteoporosis is a health risk, but HRT is not the only treatment. In view of the current controversy, doctors are now advised not to prescribe long-term treatment of HRT for prevention of osteoporosis.
Do women from all cultures suffer symptoms?
There are social, cultural and ethnic differences. Western women live in societies in which attitudes to the menopause are largely negative. By contrast, in many cultures women achieve status and gain social advantages when they reach the menopause. For example, among the Rajput of northern India, women who are past their menopause are no longer in purdah and are able to move freely within their community. Similarly, the New Zealand Maori view their post-menopausal years as a relief from child-bearing.
Japanese women report a lower frequency of symptoms than American and Canadian women; the same is true for Navajo Indians. Thus, while the menopause can be considered as the beginning of an oestrogen-deficient state and will become an increasing health problem as longevity increases, cultural influences can affect the way women experience it. It is, however, difficult to separate cultural and social influences from ethnic and genetic factors.
One of the reasons the menopause still retains a negative social construct in the West is that it is a sign of ageing. And for many women it not only signals loss of fertility, and thus the end of a younger phase of life, but can also coincide with children leaving home (empty nest syndrome), loss of sex drive and sagging relationships with partners.
Thus the menopause can be compounded by life changes which, in themselves, can lead to depression, tearfulness, loss of confidence and inability to cope. Men may despair of the menopausal woman and seek younger playmates, but perhaps this is a result of their own "menopause" - the andropause.
While men don't suffer a sudden drop in their male hormones, their androgens, along with their sex drive, decline with age and, like women, they can also suffer a mid-life crisis.
Is it all downhill after the menopause?
There are positive sides. No more bleeding, no more tampons, no more contraception. Children leaving home can mean more time for personal and career pursuits and eventually, when many of the symptoms have subsided, there is a sort of re-emergence of oneself.
But there is a strange silence around menopause. Is this because women feel it is an admission of getting old, a stigma of not being able to cope either physically or mentally, or being loath to admit they can no longer have children? Or that they no longer see themselves as sexual beings? It's a complex issue, but when you are burning up in the classroom, sweating in an important meeting and feeling drained of physical or emotional motivation, what do you say? "Sorry, I am menopausal, I'm getting old, grey-haired and flabby"?
We need to change perceptions of the menopause. Increasing longevity means that we may spend nearly half our lives in a post-menopausal state. It's not a question of growing old gracefully, it's a matter of living a large part of our lives without much of our sex hormones. This is perfectly reasonable, provided you stay young in mind, physically active (a good preventive measure against osteoporosis) and have a healthy diet. HRT may help overcome extreme symptoms, but it is not a lifelong solution. A better understanding of the problems, more communication between friends and colleagues, and more acceptance of the menopausal transition could be of huge benefit.
* NHS Direct On Line Health Encyclopaedia: www.nhsdirect.nhs.uken.aspx?articleID=246
* The Menopause Amarant Trust (www.amarantmenopausetrust.org.uk) is a charity that aims to help women deal with problems they might experience during the menopause.
* Is It Me or Is It Hot in Here?: a modern woman's guide to the menopause, by Jenni Murray (Vermilion, pound;7.99) * Dr Miriam Stoppard's Natural Menopause, by Dr Miriam Stoppard (Dorling Kindersley, pound;4.99).
And from the clinical side
* Management of the Menopause: the handbook, by Margaret Rees and David W Purdie (Royal Society of Medicine Press, pound;19.95).
* Your Menopause Bible by Dr Robin Phillips (Carroll Brown Publishers, Pounds 19.99).
Saffron Whitehead is professor of endocrine physiology at St George's University of London medical school. She will host an online discussion on the menopause for TES readers on Wednesday, May 10, from 3.30pm until 5pm.
Go to www.tes.co.ukclinics Main text: Saffron WhiteheadAdditional Research: Sarah Jenkins Next week: the first of a four-week Friday forum on worklife balance