Perimenopause: symptoms and when it starts

What is perimenopause?

Perimenopause is the time from when your hormones start to fluctuate until twelve months after your last period. Only then, in retrospect, is menopause counted – the actual point in time of your final period.

What sets perimenopause apart from the years that follow is that oestrogen doesn't just decline – it swings. Levels can be higher than usual one month and low the next. It's these fluctuations that cause many of the symptoms, and they explain why symptoms come and go.

Researchers divide the transition into phases using the so-called STRAW+10 model: early perimenopause with irregular cycles, and late perimenopause when periods start being absent for 60 days or more.

When does perimenopause start?

Most women notice the first signs between the ages of 40 and 45. The final period arrives on average at around 51–52, so count backwards: four to eight years of transition is the norm.

Some notice changes as early as around 35, others not until after 45. Heredity plays a big role – it's worth asking your mother when it started for her. Smoking brings menopause forward by one to two years on average.

If periods stop completely before 40, it's called premature ovarian insufficiency, and before 45, early menopause. Both should be investigated by a doctor, since early loss of oestrogen affects bones and heart and often warrants treatment.

What are the most common perimenopause symptoms?

Your periods are the clearest signal: cycles become shorter, longer or get skipped. Beyond that, these symptoms are the most common:

• Irregular periods and a changed bleeding pattern – often heavier or lighter than before
• Hot flushes and night sweats
• Sleep problems, often waking in the middle of the night
• Mood swings, irritability or low mood
• Brain fog – poorer focus and short-term memory
• Tiredness that doesn't go away with rest
• Vaginal dryness and reduced sex drive
• Joint pain and stiff muscles
• Heart palpitations
• Tender breasts

Symptoms can persist for a long time. In the American SWAN study from 2015, the median duration of hot flushes and night sweats was 7.4 years – and longest for those whose symptoms began early in perimenopause.

Why does this happen? Oestrogen has receptors throughout much of the body: in the brain's temperature regulation, in skin and mucous membranes, in joints and in the signalling systems for mood and sleep. When levels are thrown between high and low, all of these systems react at once.

Two things are worth remembering. First, symptoms vary enormously – roughly one in five women barely notices the transition, while others find daily life seriously affected. Second, symptoms often come in waves, with better and worse periods in step with the hormonal swings.

How long does perimenopause last?

Four to eight years is typical, but the range is wide. Perimenopause formally ends twelve months after your last period. Some symptoms, such as hot flushes and vaginal dryness, can however continue several years into postmenopause.

The late phase, when periods are absent for two months or more, tends to be the most symptom-heavy. That's when hormone swings are at their greatest, and when hot flushes and sleep disturbances are most common. The table below shows the whole course in brief.

Is it perimenopause – or something else?

Several conditions resemble perimenopause. Thyroid disorders cause tiredness, mood changes and menstrual disturbances. Iron deficiency causes tiredness and palpitations, especially with heavy bleeding. Prolonged stress can produce an almost identical picture.

A blood test from your doctor can rule out thyroid problems and iron deficiency. Do ask for ferritin – the body's iron stores – to be checked, not just your haemoglobin. Hormone tests, on the other hand, are unreliable as a "menopause test" in this phase, precisely because levels swing from week to week.

Depression also deserves a word of its own. Low mood in perimenopause is common and hormonally understandable, but persistent low mood that takes over daily life should be taken as seriously as in any other phase of life. Don't hesitate to seek help.

Seek medical care if you bleed very heavily, bleed after sex, have bleeding after twelve months without periods, or develop clear symptoms before the age of 40.

What can ease the symptoms?

The basics first: regular exercise, fixed sleep times and less alcohol and caffeine in the evening dampen both hot flushes and sleep problems for many women. Strength training also protects muscles and bones, both of which are affected as oestrogen declines.

A few concrete habits many women find helpful:

• Do cardio or strength training at least three times a week
• Keep the bedroom cool and go to bed at the same time every night
• Cut back on alcohol, caffeine and spicy food if they trigger your flushes
• Track cycles and symptoms in an app – the pattern makes symptoms easier to understand and makes medical appointments easier

For pronounced symptoms, hormone therapy is the most effective option – talk to a gynaecologist or your doctor about what suits you. Treatment is tailored to age, symptoms and risk factors, and can be reassessed along the way.

On the nutrition side, it's about covering your needs for calcium, vitamin D, magnesium and omega-3. We've gathered what's worth taking in our guide to supplements during menopause and in our overview of vitamins for women by life stage. Many women in this phase are also curious about the herb ashwagandha – read more in our article on ashwagandha for women. You'll find products selected for this life stage in our perimenopause collection.

Frequently asked questions

Can perimenopause start as early as 35?

Yes, although it's less common. In some women, hormones start to fluctuate between 35 and 40, often with shorter cycles as the first sign. Heredity is the strongest factor. If you have clear symptoms or menstrual disturbances before 40, you should however always have it investigated by a doctor, since other causes need to be ruled out first.

Can you get pregnant during perimenopause?

Yes. Ovulation happens irregularly but continues right up until menopause, so pregnancy is entirely possible even though fertility is lower. If you don't want to become pregnant, you need to use contraception until twelve months have passed since your last period. Talk to your doctor or midwife about what protection suits this phase.

Is there a test that shows I'm in perimenopause?

There is no definitive test. Hormone levels swing sharply from week to week during perimenopause, so a single blood test for FSH or oestrogen says little. In practice, the diagnosis is based on age, menstrual pattern and symptoms. Blood tests are used rather to rule out other causes, such as a thyroid disorder or iron deficiency.

What is the difference between perimenopause and menopause?

Menopause is a point in time: your final period, confirmed retrospectively after twelve months without bleeding. Perimenopause is the years of hormonal fluctuation before and just after that point. In everyday speech, "the menopause" is often used for the whole transition – in practice covering both perimenopause and the first years after the final period.

Do supplements help with perimenopause symptoms?

Supplements don't treat the symptoms, but they can cover needs that become more important now. Calcium and vitamin D are needed for the maintenance of normal bones, magnesium contributes to a reduction of tiredness and omega-3 to normal heart function. For severe symptoms, medical advice and possibly hormone therapy is the right route.

Sources

1. 1177 – Menopausal symptoms
2. Harlow et al. 2012 – Executive summary of STRAW+10: addressing the unfinished agenda of staging reproductive aging
3. Avis et al. 2015 – Duration of menopausal vasomotor symptoms over the menopause transition (SWAN)
4. Delamater & Santoro 2018 – Management of the Perimenopause, Clinical Obstetrics and Gynecology
5. Swedish Food Agency – Vitamin D