Other experts agree. “Some health professionals get their female patients tested for things like thyroid problems, without considering that perimenopause might be at the root of their symptoms,” says Dr Ruqia Jafar, a GP specialising in perimenopause who works at Future Woman which specialises in women’s hormone health.

So what is perimenopause?

Perimenopause is the extended phase prior to menopause, and it’s when the symptoms like hot flushes and brain fog first start to occur.

“During perimenopause, hormone levels start to change, sometimes as much as seven years before the menopause – which is when your periods actually stop – so you can get fluctuations in hormones for five to seven years,” says Abernethy.

The symptoms vary enormously from person to person, but they can be alarming, especially if you don’t realise that the physical, mental and emotional changes you’re experiencing are down to your hormones. These changes can include increased feelings of depression – in fact, women are 40% more likely to experience depression during perimenopause.]

Early perimenopause

“In the very early stages, our cycles are still regular, but we may be producing less progesterone each time we ovulate, which means that the second half of the cycle becomes a bit shorter. At this stage you may experience a heavier period, which might be more painful than normal,” says Dr Jafar.

You may also find that you are having difficulty sleeping as progesterone is a sedative hormone. “For the same reason, you may get headaches and migraines, and also start experiencing your first hot flushes and night sweats,” she adds.

Second stage of perimenopause

In this stage you’re still having cycles, but they’re becoming a bit less irregular. “You might have a 28-day cycle one month and a 32-day cycle the next, which means that your progesterone is low, and your oestrogen is very up and down at this stage,” says Dr Jafar.

Because of these fluctuations you may experience both the symptoms of higher oestrogen levels – a heavy period, migraines and breast pain – and symptoms of low oestrogen, like worsening hot flushes and night sweats.

“And some women get allergy-related symptoms, like rashes and food sensitivities, because oestrogen is linked to histamine which the body releases when you’re having an allergic reaction,” says Dr Jafar.

The third stage of perimenopause

“You know you’re in the third stage when you have your first cycle that’s longer than 60 days. You’ll also notice more of the low oestrogen symptoms: night sweats, hot flushes, fatigue and joint pains,” says Dr Jafar. Symptoms like heavy periods and tender breasts tend to ease at this stage.

The fourth stage of perimenopause

Your periods are over, but it hasn’t yet been 12 months since your last period so you’re not in menopause yet. A mixture of the low oestrogen and progesterone in the system means having hot flushes and night sweats, as well as weight gain around the tummy.

“You might notice sleep issues are continuing, and you may get vaginal dryness. Aches and pains are becoming more prominent at this stage. Perhaps your mood is a bit more stable because you’re getting less of those high and low oestrogen fluctuations,” says Dr Jafar.

Six signs that perimenopause is ending

Less frequent periods

“When your periods get further apart it’s a sign that you’re getting closer to menopause,” says Abernethy. “In the run-up you may well miss three months or six months of periods and that’s a sign that your menopause is coming close”.

Increase in hot flushes. Many women find that their hot flushes and night sweats get worse in the final stages of perimenopause.

Improvement in mood

“Oestrogen is important for the production of neurotransmitters like serotonin in the brain so fluctuations can cause mood issues,” says Dr Jafar. So, your moods stabilising is a sign you’re near the end of this perimenopausal phase.

Less sleep

Poor sleep is a feature of the perimenopause, and the increased frequency of night sweats exacerbates the problem in the final stages.

Vaginal dryness

Vaginal dryness is thought to affect between half and three-quarters of perimenopausal or menopausal women and is common towards the end of perimenopause. Unlike most menopause symptoms, it’s unlikely to improve on its own and tends to get worse with time if left untreated.

Changes in libido

A decrease in sexual desire is related to low oestrogen and low testosterone, both of which decrease towards the later stages of perimenopause.

Managing perimenopause symptoms

Cognitive behavioural therapy (CBT)

“It doesn’t actually reduce the number of symptoms such as low mood, anxiety and hot flushes, but the evidence suggests that CBT helps you to learn to live with them,” says Abernethy.

Black cohosh

“There is some evidence that taking [the herb] black cohosh helps reduce hot flushes, but you should get advice before taking it – it’s not suitable if you’ve had breast cancer, for example,” says Abernethy.

Diet and exercise

In the early stages of perimenopause, the emphasis should be on helping your body become better at detoxifying oestrogen, says Dr Jafar, suggesting foods such as flax seeds and berries. Later in perimenopause, focus on raising oestrogen levels by eating more protein and good fats. Being active can significantly reduce stress, improve sleep and ease symptoms as you go through this transition, so make sure you exercise regularly.

Hormone replacement therapy (HRT)

For some women, if they’re medically suited to it, hormone replacement therapy, or HRT, can help with the symptoms of perimenopause. “But it’s important that whoever is treating you has a really clear understanding of the stage of perimenopause you’re at, based on your symptoms, as this will dictate which treatment is right for you,” adds Dr Jafar.