Am I in Perimenopause? The signs, the stages, and what to do next

If you've been feeling different lately and can't quite put your finger on why, you're not alone. Maybe your periods have changed. Maybe you're exhausted in a way sleep doesn't fix. Maybe you've developed anxiety that appeared from nowhere, or you're lying awake at 3am for no reason. And maybe you've typed "am I in perimenopause?" into Google at least once.

A recent global study of nearly 18,000 women found that one in three women over 35 aren't sure whether they're in perimenopause. That's not because the symptoms aren't there. It's because nobody told them what to look for. In this article, we cover what perimenopause actually is, when it starts, the signs and stages, how to know if it's happening to you, and what to do next.

What is perimenopause?

Perimenopause is the transitional phase before menopause, when your ovaries gradually produce less oestrogen and progesterone. It's not a single event. It's a process that unfolds over several years, during which your hormone levels fluctuate unpredictably rather than declining in a straight line.

This is an important distinction. Many women expect perimenopause to feel like a gradual winding down. In reality, oestrogen can spike higher than it ever did during your regular cycles before dropping sharply, sometimes within the same month. It's these erratic fluctuations, rather than a simple decline, that cause the wide range of symptoms women experience.

Menopause itself is a single point in time: the day that marks 12 consecutive months since your last period. Everything before that point is perimenopause. Everything after is postmenopause.

The average age of menopause in the UK is 51. Perimenopause typically begins 4 to 8 years before that, though the timing varies widely.

When does perimenopause start?

Most women begin to notice perimenopausal changes between the ages of 44 and 47, with the average age of onset around 47 in the UK. However, some women experience symptoms from their late 30s, and for others it doesn't begin until their early 50s.

Perimenopause before the age of 40 is known as premature ovarian insufficiency (POI), which affects approximately 1 in 100 women. Between 40 and 45, it's considered early menopause, affecting roughly 1 in 20 women.

Several factors can influence when perimenopause begins. Genetics is the strongest predictor: your mother's age at menopause is a useful (though not definitive) guide. Smoking tends to bring the transition forward by 1 to 2 years. Body weight, ethnicity, and certain medical treatments (including some cancer therapies and surgeries) can also affect timing.

If you're under 45 and experiencing symptoms, it's worth speaking to your GP. Earlier perimenopause may require different management and monitoring.

The stages of perimenopause

Perimenopause isn't one uniform phase. Clinicians use a staging system called STRAW+10 to map the reproductive transition, but in practical terms, most women experience perimenopause in two broad stages.

Early perimenopause

Your menstrual cycles start to change. They might become shorter, longer, heavier or lighter than what's been normal for you. The key marker is a shift of seven days or more in your cycle length compared to what you're used to. You might also notice subtler symptoms: fatigue, mood changes, sleep disruption, or PMS that feels worse than it used to. Many women don't connect these changes to perimenopause, especially if their periods are still coming regularly. This stage can last several years.

Late perimenopause

Your cycles become noticeably irregular. You start skipping periods, with gaps of 60 days or more between them. Symptoms tend to intensify during this stage: hot flushes and night sweats are more likely to appear, sleep disruption can worsen, and symptoms like brain fog, joint pain and mood changes may become more pronounced. This stage typically lasts 1 to 3 years before your final period.

It's worth noting that the transition between these stages isn't always clear-cut. Symptoms can come and go. You might have a few months of intense symptoms followed by a period of feeling relatively normal. That unpredictability is itself a hallmark of perimenopause.

The signs and symptoms

Perimenopause can produce a wide range of symptoms. Not every woman will experience all of them, and severity varies enormously. Some women sail through with minimal disruption. Others find it significantly affects their daily life, their work and their relationships.

Here are the most commonly reported symptoms, grouped by category.

Menstrual changes

• Shorter or longer cycles than usual
• Heavier or lighter periods
• Skipped periods
• Spotting between periods
• Worsening PMS

Sleep and energy

• Difficulty falling asleep or staying asleep
• Waking at 3am or 4am and not being able to get back to sleep
• Fatigue that doesn't improve with rest
• Physical and mental exhaustion

Mood and cognition

• Anxiety (new or worsening)
• Irritability and rage
• Low mood or depressive episodes
• Brain fog: difficulty concentrating, losing words, forgetfulness
• Loss of confidence or motivation

Physical changes

• Hot flushes and night sweats
• Weight gain, particularly around the middle
• Joint pain and stiffness
• Heart palpitations
• Headaches or migraines
• Dry skin, hair thinning or hair loss
• Changes in body odour

Gut and digestion

• Bloating
• Changes in bowel habits
• New food sensitivities
• Increased histamine reactions (worsening allergies, hayfever)

Other

• Reduced libido
• Vaginal dryness
• Urinary changes (frequency, urgency, UTIs)
• Tinnitus
• Electric shock sensations
• Burning or tingling in the extremities

The symptoms you might not expect

Most women know about hot flushes. Far fewer are prepared for the rest. A global study of nearly 18,000 women published in Menopause journal in 2026 revealed a significant gap between the symptoms women expect during perimenopause and the ones they actually experience.

The most recognised symptoms were hot flushes (71%), sleep problems (68%) and weight gain (65%). But the most commonly reported symptoms among women over 35 who were in perimenopause were fatigue (83%), physical and mental exhaustion (83%), irritability (80%), depressive mood (77%), sleep problems (76%), digestive issues (76%) and anxiety (75%).

Hot flushes, the symptom most associated with perimenopause in popular culture, ranked lower than all of these. This matters because women who are experiencing fatigue, gut problems and mood changes may not connect them to hormonal changes, and may spend months or years seeking explanations elsewhere.

Other symptoms that frequently catch women off guard include tinnitus (ringing in the ears), changes in body odour, worsening allergies and histamine reactions, electric shock sensations, heart palpitations, and frozen shoulder. We've covered many of these in detail on the journal. If you've experienced something you can't explain, there's a good chance it's hormonal.

How do I know if it's perimenopause?

If you're over 40 and experiencing a combination of the symptoms listed above, particularly alongside changes to your menstrual cycle, there is a good chance you are in perimenopause.

There's no single test that confirms it. The most useful tool is your own awareness: what's different, when did it start, and does it follow a pattern linked to your cycle?

Tracking your symptoms and your periods for two to three months gives you (and your GP, if you decide to visit) a much clearer picture than a one-off appointment where you're trying to remember everything on the spot. Note when symptoms appear, how intense they are, and whether they correlate with certain points in your cycle.

Some useful questions to ask yourself:

• Have your periods changed in length, flow or regularity in the last year?
• Are you experiencing symptoms you didn't have two or three years ago?
• Do your symptoms worsen at certain points in your cycle (around ovulation or in the days before your period)?
• Have you noticed changes in your sleep, mood, energy, digestion or cognition that don't have another obvious explanation?
• Is your mother's age at menopause consistent with you being in the transition now?

If you answered yes to several of these, perimenopause is a likely explanation.

Do I need blood tests?

For most women over 45, the answer is no. Current NICE guidelines state that perimenopause in women over 45 should be diagnosed based on symptoms and menstrual history, not blood tests.

The reason: hormone levels during perimenopause fluctuate so dramatically that a single blood test is unreliable. Your FSH (follicle-stimulating hormone) could be in the "normal" range one week and elevated the next. A normal result doesn't mean you're not in perimenopause, and an elevated result doesn't necessarily confirm that you are.

Blood tests may be helpful in specific situations: if you're under 45 and your GP wants to investigate further, if premature ovarian insufficiency is suspected, if you've had a hysterectomy (so there are no periods to track), or if your GP wants to rule out other conditions with similar symptoms (such as thyroid disorders, anaemia or vitamin D deficiency).

If your GP offers a blood test and the result comes back "normal," that does not mean your symptoms aren't real or aren't hormonal. It means the test may have been taken at a point when your levels happened to be within range. Your symptoms are the most reliable guide.

What to do next

If you think you're in perimenopause, there are several practical steps you can take right now.

1. Start tracking

Keep a simple record of your periods and symptoms for two to three months. When do they appear? How intense are they? Do they follow a pattern? Apps like Flo, Clue or Balance can help, or a notebook works just as well. This information is invaluable if you decide to visit your GP.

2. Talk to your GP

You don't have to wait until symptoms are severe. A conversation with your GP can help you understand your options, rule out other conditions, and start a plan. If your GP is dismissive, ask to see a different doctor or request a referral to a menopause clinic. You deserve to be heard.

3. Prioritise sleep

Sleep is the foundation. Poor sleep worsens almost every other perimenopause symptom, from brain fog and mood to weight gain and immune function. Prioritising sleep hygiene, reducing caffeine after midday, keeping your bedroom cool and dark, and establishing a consistent routine can all help. Our guide to perimenopause and sleep covers this in detail.

4. Move your body

Regular exercise, particularly a combination of strength training and aerobic activity, supports muscle mass, bone density, metabolic health, mood and sleep during perimenopause. You don't need to overhaul your routine. Consistency matters more than intensity.

5. Eat enough protein

Most women in perimenopause need more protein than they're currently eating. Aim for 25 to 30g at each meal to support muscle maintenance, blood sugar stability and satiety. Our guide to protein in perimenopause breaks this down in detail.

6. Support your gut

Your gut microbiome plays a direct role in how your body metabolises hormones, manages inflammation and regulates mood. During perimenopause, the gut is affected by hormonal changes, which can lead to bloating, digestive issues and increased sensitivity. Supporting your microbiome with a diverse range of plant foods, fibre-rich foods and targeted probiotics can help.

7. Explore your options

There are effective treatments available for perimenopause symptoms. These include HRT (hormone replacement therapy), which addresses the hormonal root cause; lifestyle and dietary changes; targeted supplements; and in some cases, cognitive behavioural therapy (CBT) for specific symptoms like hot flushes and sleep disruption. The right approach depends on your individual symptoms, medical history and preferences.

When to see your GP

You can see your GP at any point if you think you're in perimenopause. You don't need to reach a certain level of suffering before the conversation is worthwhile. Early recognition means earlier support.

However, there are some situations where it's particularly important to seek medical advice:

• You're under 45 and experiencing perimenopausal symptoms
• Your periods have become very heavy, very close together, or you're bleeding between periods
• You're experiencing post-coital bleeding (bleeding after sex)
• You're having bleeding after 12 months without a period
• Your symptoms are significantly affecting your work, relationships or quality of life
• You're experiencing persistent low mood, anxiety or thoughts of self-harm
• You have new or unexplained pelvic pain
• You want to discuss HRT or other treatment options

When you do visit your GP, bring your symptom tracker. Be specific about what you're experiencing, when it started, and how it's affecting you. If your GP doesn't take your concerns seriously, you have the right to ask for a second opinion or a referral.

The bottom line

If you're reading this and thinking "that's me," you're probably right. Perimenopause is not a diagnosis you need to be given by someone else. It's a transition your body is going through, and recognising it is the first and most important step.

You're not imagining it. You're not "just stressed." And you're not alone. One in three women aren't sure if they're in perimenopause, which means millions of women are experiencing symptoms without understanding why. The fact that you're here, looking for answers, puts you ahead of most.

There is support available, there are effective treatments, and there are things you can do right now to feel better. Start by tracking your symptoms, talk to your GP, and take it from there. You deserve to understand what's happening in your body.

This article is for informational purposes and is not a substitute for professional medical advice. If you have concerns about perimenopause, menopause or any of the symptoms described, please speak to your GP or a qualified healthcare provider.