For the Olympic gold medal-winning athlete Kelly Holmes, one of the first warning signs that something had changed was struggling to sleep.

Throughout her career as an athlete, good sleep had always been a priority – and easy to obtain. But a couple of years ago, then aged 51, she started struggling to fall asleep, and waking around 3am. It was only when a doctor told her this was a symptom of the perimenopause that she realised what was happening.

She said: “I’ve been an active person – when your energy is going down, when your emotions are heightened, you feel stressed in the morning – it’s not a nice way of living. If you don’t get a good night’s sleep you’re ratty before you’ve even started.”

She still struggles with the symptoms: she may get six hours on a good night, but four or five is more common.

Holmes’s experience is reflected in National Institutes of Health statistics, which suggest that sleep disturbance occurs in 16-42% of women before menopause, from 39-47% during perimenopause, and from 35-60% after menopause.

Despite being one of the most common symptoms, many women – including those she meets on menopause roundtables – are unaware, said Holmes.

A poll of 2,005 perimenopausal and menopausal women by Censuswide for Dunelm found that three-quarters had experienced menopausal insomnia, yet more than half did not realise it was a symptom. More than two-thirds (69%) said it had a negative impact on their emotional wellbeing.

Most women woke up at 3.29am, when the majority lay in bed and tried to fall back to sleep, while others read a book, scrolled on social media or watched TV.

Prof Matthew Walker, a sleep scientist and author of How We Sleep, said menopausal women experience insomnia because of hormonal changes and hot flushes.

Sleep disruption on this scale poses serious public health challenges, he says, as chronic sleep loss can increase the risk of cardiovascular disease, obesity and weakened immune system, as well as worsening mental health, including depression, anxiety, irritability and mood swings, and a broader quality of life impact, such as chronic fatigue, decreased productivity and a lack of enthusiasm for life.

Many women can be helped with lifestyle changes including cutting out caffeine and alcohol, said Dr Zoe Schaedel, a GP and British Menopause Society specialist. For some women, HRT can help by boosting oestrogen levels.

Holmes said that closing her curtains at night had helped, along with taking time to relax with a warm bath before bed, keeping her bedroom screen-free and switching to cooler cotton bedding.

However, Schaedel said in some cases the sleep problem will have become a habit, in which case a doctor may diagnose insomnia disorder or chronic insomnia if sleep disruption has occurred for at least three nights a week, for three months or more. Women may be offered cognitive behavioural therapy for insomnia (CBT-I), or medication.

She added that workplaces should offer support to menopausal women by allowing them to work flexibly. “That is what most women mention as being helpful about work – if they can start a bit later, that can make a big difference.”

Dr Hana Patel, a GP specialising in women’s and mental health, said she saw lots of patients who were experiencing perimenopause or menopause with problems sleeping, resulting in irritability, difficulty concentrating and anxiety. She assures them that “this is a temporary symptom and there are treatments to help”.

For many women, a good starting point is following a regular sleep schedule by going to bed and waking up at the same time every day, developing a relaxing bedtime routine such as reading a book or taking a warm bath, and avoiding screens in the bedroom. Keeping the bedroom cool, well-ventilated, dark and as quiet as possible can also help, as can sleeping alone, she said.

The science behind insomnia in the menopause

There are two known, and distinct, causes of insomnia in the menopause: one is hormonal changes, the other is hot flushes.

The hormonal changes that women experience during the menopause include a reduction of oestrogen and progesterone. Both of these promote sleep, says Matthew Walker.

Oestrogen enhances serotonin, a neurotransmitter linked to sleep regulation, so when oestrogen levels decline it can result in disturbed sleep. Progesterone has “more of a sedative property”, he says, and its decline can also contribute to difficulties falling and staying asleep.

The second is hot flushes, which are caused by dilations and constrictions of the blood vessels. These disrupt sleep because they predominantly happen at night, and can cause night sweats and thermoregulation difficulties.

“We need to drop our core body temperature by almost about 1 degree celsius to fall asleep and stay asleep. That’s why you’ll find it easier to fall asleep in a room that’s too cold than too hot,” says Walker.

Dr Zoe Schaedel says most women experience “sleep fragmentation”, meaning they do not struggle to fall asleep or wake early, but struggle to remain asleep during the night.

In addition to the two main causes, poor sleep can also be caused by depression arising from the menopause, since 80% of people with depression have insomnia, says Schaedel. It can be related to needing to wake up to urinate in the night, another menopausal symptom, and ageing more broadly, as sleep quality decreases with age and stress levels are high in midlife.

Schaedel and Walker agree that far more research is needed on this issue, with unanswered questions ranging from ethnic differences to whether there could be a link between menopausal insomnia and increased risk of dementia.