Pictured: Joscelyn Leggett, 52, who was working in sales with her husband Mike when, in her late 40s, she began to suffer from ‘black’ depressions

The onset of Teresa Bagnall’s menopause signalled a sudden and catastrophic change in both her personality and appearance.

‘I was in my mid-40s when it hit me like a bus,’ she says. ‘I had these awful night sweats. The bed would be continuously wringing wet and I’d have to get up and change the sheets. One night I woke up drenched 11 times.

‘During the day I had such terrible hot flushes I started to wear a sweatband round my head, but it got soaked.

‘My hair was perpetually lank and wet and my clothes were saturated. It was embarrassing and degrading. I felt unclean.

‘I’m still exhausted; mentally and physically drained. I used to be immaculately presented: perfect make-up, not a hair out of place.

‘I’m tall — 5 ft 10 in — and I was always a size 12, but I have ballooned to a size 20 and I feel repulsive.

‘The old Teresa was jolly, kind and full of life. Now I’ve lost all my self-confidence and I hardly ever go out. My husband is so understanding. He says: “I know the old Teresa is in there somewhere and one day she’ll come back.” But some days I wonder if she ever will.’

So profound was the impact of her symptoms that Teresa, 46, from Leicester, found her job as a health care support worker in an NHS hospital ward for the elderly untenable.

To her abiding regret, the work she once did with such proficiency became a daily challenge she could no longer face, her exhaustion compounded by the stifling heat on the ward.

‘My uniform was thick: non-breathable black trousers, a heavy poly-cotton top and stout shoes. The ward was so hot and airless even patients were saying they felt faint. The radiators couldn’t be turned down as they were controlled from a central point off the premises. It was like working under a red-hot sun with no fresh air. In my breaks I’d sit in my car with the air-conditioning on full.

‘I was in charge of supplies — needles, bandages, plasters, pads — and as my mind was so fogged with fatigue and the heat, I worried I wasn’t doing things right.

‘I’d check everything over and over again. I never dared close my eyes at work as I knew I’d fall into a deep sleep.’

Sensibly in the circumstances — knowing, too, that many patients had also complained about the stifling heat — Teresa opened the windows. ‘But as they were covered in mesh for the protection of the patients, many of whom had dementia, it didn’t make much difference,’ she recalls.

Then, to her distress, she was reprimanded. ‘The matron called me in and said a “serious complaint” had been made against me, apparently by a member of the administrative staff, that I kept opening the windows.

‘I felt myself flush. I said, “Yes, it’s because I’m hot,” and the (male) matron replied: “Some people are cold.” I pointed out that those who were cold could put on extra layers, but I couldn’t wear anything less.

‘The matron asked if there was a reason why I was hot and I said, “Yes, I’m going through the menopause”. He then asked, “Should you really be here then, in this job?” and I felt my mouth drop open. I was so disheartened that I burst out crying.’

At a subsequent meeting Teresa was told she was ‘unsuitable’ for the role. As it was a new post and she was still on a probationary period, she left without a challenge.

Besides, depleted and worn out, she had no energy to contest it.

Today Teresa, mum to two sons aged 26 and 23, and married to her second husband Carl, 53, a delivery driver, is a temporary worker on the NHS staff bank.

Unable to manage a full-time job — she still endures severe menopause-related depression, although HRT has helped — she now works just two days a week.

Teresa’s experience is far from rare. While the toll the menopause takes on women’s personal lives is well documented, research has, until now, failed to uncover the full force of its impact on the UK workforce and economy.

Lorraine Hegarty (pictured), 54, was the archetypal busy, stressed working mother when, 12 years ago, she began to suffer the incapacitating effects of an early menopause, brought on by the hysterectomy she’d had aged 30

So the publication a fortnight ago of a review commissioned by the Department for Education and carried out by the University of Leicester, which collated 26 years of research into the menopause, broke new ground.

It highlighted the gaps in understanding about the true cost of the menopause to mid-life women at work — there are estimated to be 4.3 million over 50 in employment, and the figure is rising. It found they often feel too afraid to admit to problems for fear of losing their jobs.

It also noted the paucity of support and suggested Government-funded research into alleviation and management of symptoms would ease the burden on women and the economy.

A separate survey last week revealed that as many as 8 million mid-life women struggle with symptoms that affect their work. Of 1,000 women questioned by Maryon Stewart, author, campaigner and expert in women’s hormone health, 84 per cent reported symptoms that reduced their productivity at work.

The survey extrapolated that the true cost to women’s professional lives — as they struggle with night sweats, sleep deprivation and muddled thinking — equates to a loss of 280 million productive work days. So although middle-aged women have more freedom, work longer and have greater disposable income than previous generations, the stark fact remains that lack of knowledge and effective treatment is denying them necessary help.

The severity of the problem has now been recognised by Parliament and the All-Party Parliamentary Group on Women’s Health has pledged to debate the menopause.

So what else can be done? For Dr Sally Hope, who has long fought for parity between the sexes in the workplace, the answer is not to capitulate — or ask for time off — but to find effective solutions.

Dr Hope, 60, who represented the Royal College of GPs on the National Institute for Clinical Excellence guideline group on the menopause in 2015, says, ‘If we are aware, we can treat women with tolerance and sensitivity rather than ridicule and dismissiveness.

‘Often the menopause coincides with a dire time in women’s lives when they’re already spinning six plates in the air: they’ve got stroppy teenage children, elderly dependent parents and in-laws, a husband having a mid-life meltdown and they’re working full-time.

‘Understanding and empathy from higher management makes all the difference: decent ventilation, allowing staff to have fans on their desks and, if they have a uniform, to wear a lighter one; even a power nap at lunchtime — all this improves mood, comfort and productivity.

‘The prevailing attitude in the workplace is: why can’t they just pull themselves together and get on with it? We want colleagues who can share the load. And, of course, 30 per cent of women have no symptoms at all.

Teresa Bagnall (pictured), 46, a health care support worker who has endured such terrible menopausal symptoms she was unable to work in the hospital ward where she looked after elderly mental health patient

‘But for the other 70 per cent, the menopause hits them like a freight train. We need more awareness and an understanding of the things, like structured relaxation, exercise and diet, that really can help.’

Lorraine Hegarty, 54, was the archetypal busy, stressed working mother when, 12 years ago, she began to suffer the incapacitating effects of an early menopause, brought on by the hysterectomy she’d had aged 30.

With three children, a husband who then worked in banking in the City, and two dogs to care for, she was also working alternate night and day shifts as a midwife while studying for a degree in midwifery.

‘I loved my job and was dedicated to it,’ says Lorraine, ‘but the menopause worsened my already fragile sleep patterns. My body didn’t know whether it was coming or going.

‘I was exhausted and when I worked nights I ate lots of sugary foods for a quick energy fix, which made me feel worse. Within a couple of years I’d ballooned by four stone to 14 stone.

‘I was continually tearful and low. I’d wake up feeling as if I hadn’t even been to sleep. I just became overwhelmed and depressed. I felt rough for eight years and reached such a low point I was offered counselling. I was also put on anti-depressants. But work colleagues weren’t sympathetic. I just felt broken.’

Lorraine, like Teresa, felt her energetic personality had been usurped. ‘I used to be Tigger-like. I’d bounce out of bed in the mornings ready to take on the day. But that enthusiasm evaporated. I turned into Eeyore.

‘At my worst, I remember contemplating suicide. I sat down by the sea (we then lived by the coast in Kent) and I was frightened to go home because I thought I’d just take a load of tablets. I felt utter despair.

‘I went to a psychiatrist because I thought there was something wrong with my head. I didn’t realise the depression was linked to the menopause — neither did she.’ She took three months off work sick. Returning, the pressures of the job seemed to crush her.

She served her notice and now divides her time between her home in Malta — where her husband works — and Berkshire, where she does enough work to retain her midwifery registration.

With timely and effective help, the experienced and conscientious Lorraine could have continued to be a valued full-time employee of the NHS. As it was she floundered.

‘Like so many women, when the menopause hit Lorraine she felt she’d been possessed by an alien,’ says Maryon Stewart. ‘GPs often only offer a Band-Aid approach: HRT or anti-depressants. So many women feel scared, isolated and overwhelmed.

‘They push themselves at work as they’re scared to not appear as if they’re functioning normally, but by doing so feel more stressed. Many cling on by their fingernails, barely coping, until they’re signed off because they can’t fulfil their role any more.’

Maryon recognises, too, that having fought hard for equality at work, middle-aged women do not want to concede ground by admitting they are unable to work during the tricky menopausal years.

However she is confident that there are natural and effective ways of fighting even the worst symptoms which also restore vigour, energy and clarity of thought.

‘By getting nutrient levels into an optimum range and consuming a diet rich in naturally occurring oestrogen, you help your hormones function normally,’ she says.

‘Regular exercise is also essential, as is relaxation. Both help reduce anxiety and depression while also improving vitality and concentration.’

She also prescribes her patients tried-and-tested supplements shown in clinical trials to be safe and effective.

Joscelyn Leggett, 52, noted ‘remarkable’ benefits when she stuck to Maryon’s programme, eliminating alcohol, chocolate, wheat and caffeine from her diet for 99 days and increasing her intake of salads, vegetables, flax seeds, soya milk and beans.

Joscelyn was working in sales with her husband Mike in their print and design company when, in her late 40s, she began to suffer from ‘black’ depressions.

‘Sometimes I’d drag myself into work and just stare at a page. I’m quite driven and used to enjoy the thrill of the sale, but I just couldn’t be bothered to speak to anyone.

‘On the really black days, I didn’t get out of bed. Some weeks I didn’t go into work at all. I couldn’t function. Often I felt as if I hadn’t slept all night, while during the day all I wanted to do was sleep.

‘I’d been into fitness and nutrition, but I craved chocolate, cake, cheese and bread. I put on about a stone. I’d burst into tears for no reason. I remember one lovely summer day sitting on the sofa looking at birds and flowers in the garden and thinking, “I haven’t even got the will to sit outside.”

‘I went to the doctor’s several times and said I was absolutely exhausted. Not once did they suggest it could be the menopause.

Key to helping women cope is, it seems, to break the taboo of shame and embarrassment associated with menopause, and the unwarranted sense that a women going through it is past her sell-by date. Pictured left: Teresa Bagnall, 46. Centre: Lorraine Hegarty, 54. Right: Joscelyn Leggett, 52.

‘When I asked if it could be I was told I was too young. The doctor said, “You’re living in the fast lane.” I wasn’t. All I was doing was trying to go to work.’

Joscelyn, who lives in Northamptonshire, says Mike’s understanding helped relieve the anxiety she felt at being unable to work.

‘Mike knew I felt guilty when I couldn’t go into work,’ she says. ‘He took his foot off the gas. If he had nagged me to go in, I know that I would have felt even worse. Had I been an employee I’d probably have been forced to leave my job.’

After sticking rigidly to the eating plan prescribed by Maryon, in months she found her mood lifted and her energy was restored.

Key to helping women cope is, it seems, to break the taboo of shame and embarrassment associated with menopause, and the unwarranted sense that a women going through it is past her sell-by date.

Dr Sharron Hinchliff of the University of Sheffield carried out research into the menopause.

‘It has been a taboo topic in our society for many years. While that is beginning to change, awareness in the workplace lags behind,’ she says. ‘Being open about the ways that it can affect our mental and physical health is important. Support at work certainly helps.

‘But not all women will want their employers to know about their menopausal status. If we make a start to normalise it, however, and break the stigma that has been traditionally attached to it we will be taking one significant step in the right direction.’

- Maryon Stewart runs free live masterclasses helping women to overcome menopause naturally: maryonstewart.com/masterclass