Perimenopause doesn’t begin with your last period, in fact, it often starts long before you realise. For many women in the UK, the early signs of perimenopause appear in their late 30s or early 40s, yet are frequently mistaken for stress, exhaustion, or simply ‘getting older’. According to the NHS, perimenopause typically begins between the ages of 45 and 55 and can last for several years, but 1 in 100 women experience symptoms before the age of 40.

These early hormonal shifts can affect everything from mood and memory to sleep and bladder function,  and because they’re subtle and varied, they often go unnoticed or are misdiagnosed. It’s reported that 1 in 100 women experience symptoms.

Wondering if what you’re feeling could be hormonal? In this post, we’ll highlight the early signs of perimenopause women often miss and what to do next if these symptoms sound familiar.

1. Constant fatigue without reason

Feeling constantly tired, even after a full night’s rest, can be one of the first symptoms. This isn’t ordinary tiredness, it could be hormone related fatigue.

Why it happens:

• Fluctuating oestrogen affects energy regulation.
• Low quality sleep due to hormonal imbalances adds to exhaustion.

A survey by Balance Menopause found that over 60% of UK women experience persistent tiredness in early perimenopause (Balance).

2. Low mood, anxiety, and mood swings

Emotional symptoms often strike before physical ones. Many women report:

• Sudden anxiety without trigger
• Mood swings or irritability
• Feeling low or tearful for no clear reason

A 2022 report by the Mental Health Foundation UK noted that emotional symptoms are among the earliest indicators of perimenopause, especially for women aged 40-45.

3. Heavy/irregular periods

Your periods may:

• Come closer together or be spaced apart
• Become lighter, then suddenly heavier
• Last longer or include spotting

Bleeding is one of the key early signs of perimenopause in the UK. However, hormonal contraception may mask these signs.

4. Brain fog and poor concentration

Cognitive changes such as:

• Forgetfulness
• Trouble focusing
• ‘Woolly thinking’ (unclear or muddled thinking)

…are all linked to hormonal changes, particularly fluctuating oestrogen and progesterone levels.

Brain fog is frequently reported during the menopausal transition, with 50-60% of midlife women experiencing forgetfulness, poor concentration, and ‘woolly thinking’.

5. Bladder changes & UTIs

Fewer women associate perimenopause with urinary symptoms, but oestrogen decline affects the bladder too. You might notice:

• More frequent urination
• Urinary tract infections (UTIs)
• Mild bladder leakage when coughing or sneezing

According to Women’s Health Concern UK, urogenital symptoms affect up to 50% of perimenopausal women, often starting subtly.

6. Sudden weight gain or body shape changes

Many women gain fat around the abdomen even without changing their diet.

Why it happens:

• Hormonal shifts alter fat storage patterns
• Metabolism slows slightly
• Insulin sensitivity changes

A study by University College London (UCL) linked declining oestrogen to increased visceral fat in women entering perimenopause.

7. Breast tenderness, joint pain & tenderness

Some physical symptoms aren’t immediately tied to hormones, but they can be early flags:

• Breast soreness
• Tingling hands and feet
• Joint pain or stiffness
• Heart palpitations

The Royal College of Obstetricians and Gynaecologists (RCOG) includes joint discomfort and cardiovascular symptoms in its list of under-discussed early perimenopausal signs.

Periomenopausal Help at The Medical Hub

At The Medical Hub, our menopause initial consultations are designed to help you understand and manage perimenopausal symptoms with confidence. During your appointment, our expert healthcare team will take time to explore your symptoms, review your medical history, and explain the hormonal changes affecting your body. If appropriate, we may carry out blood tests and offer treatment options such as HRT or testosterone. Whether you’re experiencing fatigue, mood swings, brain fog, or physical changes, we provide tailored support to help you feel more like yourself again.