What Is Perimenopause? The Early Signs Every Woman Should Know

Perimenopause is the transitional phase before menopause. It can last anywhere from a few years to over a decade.

During this time, your ovaries begin producing hormones — particularly oestrogen and progesterone — less predictably. It's the fluctuation (not just the decline) of hormones that causes symptoms.

Menopause itself is defined as 12 months without a period. Perimenopause happens before that.

Hormone levels can vary dramatically from one day to the next — which is why symptoms often feel inconsistent and confusing.

Many women assume perimenopause only means hot flushes. In reality, symptoms can start years earlier and look very different.

Common early signs include:

• Changes to your menstrual cycle (shorter, longer, heavier or lighter)
• Anxiety or low mood — For a deeper look at why anxiety can appear suddenly in midlife, read our article on anxiety during perimenopause.
• Brain fog or forgetfulness
• Poor sleep — If you're waking at 3am or struggling with night sweats, we explain the hormonal causes in our post on perimenopause and insomnia.
• Night sweats
• New or worsening PMS
• Fatigue
• Reduced libido
• Breast tenderness
• Heart palpitations — Many women also notice changes in weight distribution during this stage. We explore this in detail in our article on perimenopause weight gain.

If several of these feel familiar, hormone fluctuations could be the cause.

If you're nodding along to more than a few of these, our free perimenopause assessment can help you identify whether perimenopause is likely — and what your next steps could be. It takes just a few minutes and gives you tailored guidance.

For decades, women's hormone health wasn't widely discussed. Many of us weren't taught what perimenopause actually involves.

You might be told:

Whilst ageing is natural, struggling doesn't have to be.

The earlier you understand what's happening hormonally, the sooner you can make informed, evidence-based decisions about support.

For most women, perimenopause begins between 35 and 45 — but it can start earlier.

If you still have periods (even irregular ones), you could be in perimenopause.

Importantly, diagnosis in women over 45 is usually based on symptoms — not blood tests — because hormone levels fluctuate daily.

This is why understanding your pattern of symptoms matters.

You can review a full perimenopause symptom checklist here to see how your experience compares.

If you think you might be going through perimenopause:

• Track your symptoms
• Track your cycle
• Speak to your GP about your concerns
• Learn about your hormone health

And with the right knowledge and personalised support, you can navigate it confidently.