---
title: 'What Are the First Signs of Perimenopause?'
slug: perimenopause-first-signs-starting-what-to-expect
lifeStage: perimenopause
category: Cycle
medicalReviewer: "Dr Rebeccah Tomlinson, Private GP Women's Health: Menopause Speciality"
reviewerId: 'https://blog.bloume.com/perimenopause/medical-board.md#dr-rebeccah-tomlinson'
lastUpdated: '2026-08-11'
primarySource: 'Perimenopause and menopause: your questions answered'
wordCount: 1153
readTimeInSeconds: 288.25
---

# What Are the First Signs of Perimenopause?

Perimenopause is the transition that leads up to your final period. It usually begins between the ages of 45 and 55, though it can start earlier. The first signs often include changes to your cycle, hot flushes, disrupted sleep, and shifts in mood or concentration. Oestrogen levels swing unpredictably during this time, which drives the range of symptoms you might feel. This article covers what to expect, how to tell if perimenopause has begun, and how tracking your symptoms can help.

**Q: What are the very first signs perimenopause is starting?**
A: Changes to your menstrual cycle are often among the earliest signs. Your periods may arrive more or less often than usual, become heavier or lighter, or last a different length of time. You might also notice things like disrupted sleep, hot flushes, or mood changes before your cycle becomes irregular. If you are unsure, tracking your symptoms and speaking to your GP can help make sense of what is happening.

Perimenopause is the stretch of time leading up to your final natural period, and it can start earlier than most people expect. The first signs are often easy to miss or put down to something else: a period that's slightly off, sleep that doesn't feel restorative, mood changes that seem to come from nowhere. Understanding what's happening, and why, can make this stage easier to navigate.

## When does perimenopause typically begin?

Perimenopause usually starts from the age of 45, though it can begin earlier. In the UK, the average age to reach menopause, which is 12 months in a row without a period, is 51. The years leading up to that point can run from a few months to as long as a decade, and they average around four years.

If your symptoms start before the age of 40, this is not typical perimenopause. Onset before 40 can point to Premature Ovarian Insufficiency (POI), a separate condition where the ovaries stop working earlier than usual. If this sounds like you, it is worth speaking to your GP, as POI needs its own assessment and care.

## Why oestrogen fluctuation causes so many symptoms

Some weeks can feel manageable while others are much harder, and that inconsistency is part of how perimenopause works. Most of your symptoms come down to your hormones shifting, especially oestrogen, as your ovaries gradually slow down. These shifts are often erratic and hard to predict rather than a smooth, steady decline. That is why how you feel can swing so much from week to week.

## How your cycle changes as the first sign perimenopause is starting

One of the earliest and most common signs that perimenopause has begun is a change in your usual period pattern. Your cycles might arrive more or less often than they used to. Your flow can become heavier or lighter, and your period may last a different length of time. The whole cycle can run shorter or longer than your normal.

> **WARNING**: If your periods become unusually heavy or drag on longer than usual, it is worth raising this with your GP. Heavy or irregular bleeding can have other causes that may need to be checked and ruled out.

It is also worth knowing that other symptoms can turn up before your cycle becomes irregular. Changes to your sleep, mood, or body temperature may come before you notice any shift in your periods.

## Physical symptoms to be aware of

Beyond cycle changes, a wide range of physical symptoms can show up during perimenopause. These include:

- Hot flushes
- Night sweats
- Sleep difficulties
- Headaches or migraines
- Joint aches
- Heart palpitations
- Vaginal dryness

> **WARNING**: Palpitations can happen during perimenopause. If they are persistent, severe, or come with chest pain or breathlessness, speak to your GP promptly so any heart causes can be checked.

## Psychological and cognitive symptoms

Changes to your mood and thinking are also very common during perimenopause, and they are often the symptoms that cause the most confusion. You might notice low mood, anxiety, or irritability alongside trouble with memory and concentration, sometimes called brain fog. You might also notice a dip in self-confidence.

Hormonal changes feed into these experiences. Low mood and anxiety that stick around or feel severe still deserve their own assessment. If you are struggling with your mental health, speaking to your GP is a useful first step. NHS Talking Therapies can also support you with anxiety and low mood, and your GP can refer you, or you can refer yourself in England.

## The wide range of individual experience

Symptoms and how strong they feel differ a lot from one person to the next. Perimenopause may have a real impact on your daily life, or your symptoms may be mild and barely noticeable.

## How perimenopause is assessed

If you are over 45, your GP can assess perimenopause based on your symptoms alone. Routine blood tests to check your hormone levels are not usually needed at this age, because hormone levels swing too much during perimenopause to give a reliable result. If you are under 45 and noticing symptoms, your GP may look at blood tests alongside your symptom history.

## What to track and why it helps

Keeping a record of your symptoms over time is a practical, useful step. A symptom diary helps you spot patterns, see how things are changing, and gives your GP a clearer picture when you ask for support. You might note the date and length of your periods, any physical symptoms and when they crop up, and changes to your mood, sleep, or concentration.

> **INFO**: If you use a cycle or symptom tracking tool, including any app, this is for your own awareness only. It does not replace professional medical advice or count as a clinical assessment.

If your symptoms are affecting your daily life, or you are unsure whether what you are feeling is linked to perimenopause, booking an appointment with your GP is the most useful next step. You do not need to wait until things become severe.

**Q: What are the very first signs perimenopause is starting?**

Changes to your menstrual cycle are often among the earliest signs. Your periods may arrive more or less often than usual, become heavier or lighter, or last a different length of time. You might also notice things like disrupted sleep, hot flushes, or mood changes before your cycle becomes irregular. If you are unsure, tracking your symptoms and speaking to your GP can help make sense of what is happening.

**Q: What age does perimenopause typically start?**

Perimenopause usually begins around the age of 45, and the average age of reaching menopause in the UK is around 51. It can start earlier than 45 for some. Symptoms that begin before the age of 40 can point to Premature Ovarian Insufficiency (POI), which is a separate condition and needs a GP assessment.

**Q: Do you need a blood test to confirm perimenopause?**

If you are over 45, your GP can assess perimenopause based on your symptoms alone. Routine blood tests are not usually needed at this age, because hormone levels swing a lot during perimenopause and do not give a reliable result. If you are under 45, your GP may discuss blood tests alongside your symptom history.

**Q: Can perimenopause affect mood and memory?**

Yes. Low mood, anxiety, irritability, trouble concentrating, and memory lapses are common during perimenopause and link back to fluctuating oestrogen. If these symptoms stick around or feel severe, it is worth speaking to your GP, as they may benefit from their own assessment and support alongside any perimenopause care.

**Q: How long does perimenopause last?**

The length of perimenopause varies a lot. It can run anywhere from a few months to around ten years, with an average of roughly four years before your periods stop completely. Because hormone levels swing unpredictably through this time, your symptoms can vary in intensity from week to week.

### Clinical Sources
- [Perimenopause and menopause: your questions answered](https://www.womens-health-concern.org/wp-content/uploads/2026/04/38-NEW-WHC-FACTSHEET-Perimenopause-and-menopause-APRIL2026-A.pdf)
- [Early or premature menopause](https://www.nhs.uk/conditions/early-or-premature-menopause/)
- [Perimenopause and menopause: your questions answered](https://www.womens-health-concern.org/wp-content/uploads/2026/04/38-NEW-WHC-FACTSHEET-Perimenopause-and-menopause-APRIL2026-A.pdf)
- [Understanding Menopause](https://www.womens-health-concern.org/wp-content/uploads/2023/08/MEN0921351544-005_Menopause-Support-Booklet-5-3.pdf)
- [lscft.nhs.uk](https://www.lscft.nhs.uk/services/service-finder-z/community-pain-service/perimenopause-menopause-and-pain)
- [lscft.nhs.uk](https://www.lscft.nhs.uk/services/service-finder-z/community-pain-service/perimenopause-menopause-and-pain)
- [Symptoms of menopause and perimenopause](https://www.nhs.uk/conditions/menopause-and-perimenopause/symptoms/)
- [Symptoms of menopause and perimenopause](https://www.nhs.uk/conditions/menopause-and-perimenopause/symptoms/)
- [Symptoms of menopause and perimenopause](https://www.nhs.uk/conditions/menopause-and-perimenopause/symptoms/)
- [Symptoms of menopause and perimenopause](https://www.nhs.uk/conditions/menopause-and-perimenopause/symptoms/)
- [Symptoms of menopause and perimenopause](https://www.nhs.uk/conditions/menopause-and-perimenopause/symptoms/)

---
Reviewed by Dr Rebeccah Tomlinson, Private GP Women's Health: Menopause Speciality | [Medical Board](https://blog.bloume.com/perimenopause/medical-board.md) | August 2026