Tamar Health

Published by Tamar Health · Plymouth · Health Advice

Perimenopause is one of the most significant hormonal transitions a woman goes through, and also one of the most poorly understood. Many women spend months or even years experiencing symptoms without connecting them to their hormones. Others are told their symptoms are stress, depression, or just part of getting older. This post explains what perimenopause actually is, what it feels like, and how blood tests can help clarify what’s going on.

What Is Perimenopause?

Perimenopause is the transitional phase leading up to menopause. It typically begins in a woman’s mid-to-late 40s, though it can start earlier, sometimes in the late 30s. During this time, oestrogen and progesterone levels begin to fluctuate and gradually decline. The ovaries become less predictable in their hormone output, which is what causes the wide range of symptoms associated with this stage of life.

Perimenopause ends when a woman has gone 12 consecutive months without a period. That point is defined as menopause. Everything before it, however long that transition takes, is perimenopause. For some women it lasts a couple of years. For others, it can last a decade.

What Does Perimenopause Feel Like?

The symptom picture varies enormously between women. Some experience relatively little disruption. Others find perimenopause significantly affects their quality of life, their work, their relationships, and their mental health. Common symptoms include:

• Irregular periods, cycles becoming longer, shorter, heavier, lighter, or unpredictable
• Hot flushes and night sweats
• Sleep disturbance, difficulty getting to sleep or staying asleep
• Fatigue and low energy that doesn’t resolve with rest
• Brain fog, difficulty concentrating or remembering things
• Low mood, irritability, or increased anxiety
• Reduced libido
• Joint aches and muscle stiffness
• Vaginal dryness and discomfort
• Changes in skin, hair texture, or weight distribution
• Heart palpitations

What makes perimenopause particularly difficult to identify is that many of these symptoms overlap with other conditions. Fatigue and brain fog could be thyroid dysfunction. Low mood could be depression. Irregular periods could be stress or another gynaecological issue. Without a proper assessment, it’s easy to end up being treated for the symptom rather than the underlying hormonal cause.

Why Is It Often Missed?

Several things contribute to perimenopause being missed or dismissed. Awareness has improved in recent years, but it’s still not where it needs to be. Women are sometimes told their symptoms are anxiety or depression and prescribed antidepressants without hormonal investigation. Others are told they’re too young for menopause, which is often true in the literal sense but misses the point, because perimenopause can begin years before menopause itself.

Short NHS GP appointments don’t always allow enough time to properly explore a symptom picture that affects multiple systems. And because symptoms fluctuate, a woman might feel relatively well on the day of an appointment and struggle to convey how much the collective impact has been affecting her day-to-day life.

Can Blood Tests Diagnose Perimenopause?

This is where it gets nuanced. Perimenopause is primarily a clinical diagnosis, meaning it’s based on symptoms and age rather than a single definitive test. This is because hormone levels fluctuate significantly during perimenopause and a single blood result can fall within the normal range even when symptoms are significant.

That said, hormone blood tests are still very useful for several reasons:

• They can rule out other causes of symptoms, particularly thyroid dysfunction, which can mimic perimenopause closely
• FSH (follicle stimulating hormone) tends to rise as the ovaries become less responsive, and an elevated FSH alongside symptoms is supportive of perimenopause
• Oestrogen levels can confirm hormonal changes even when they’re fluctuating
• A baseline gives useful context for tracking changes over time and assessing response to treatment

What Tests Are Available at Tamar Health?

Hormone Health Screen

Covers FSH, LH, oestradiol, testosterone, SHBG, and prolactin. A good starting point for investigating hormonal symptoms, including perimenopause, low libido, and cycle irregularities.

Menopause and Wellbeing Screen

A more comprehensive panel combining the hormone health screen with a broader wellbeing check, including thyroid function, full blood count, ferritin, vitamin D, B12, kidney and liver function, and cholesterol. Designed to give a complete picture of health during hormonal transition and rule out other contributing factors.

Both panels are processed through Nuffield Pathology, with results back the next working day. No GP referral is needed. You can find current pricing on our blood tests price page.

What Happens After Testing?

Results need to be interpreted in context. A raised FSH alongside classic symptoms in a woman in her mid-40s tells a clear story. A normal FSH doesn’t rule out perimenopause. This is why it’s valuable to discuss results with a clinician rather than just reading a set of numbers in isolation.

If your results and symptoms suggest perimenopause, the next step is usually a consultation to discuss management options. These range from lifestyle measures and symptom-specific treatments through to Hormone Replacement Therapy (HRT), which has become significantly more accessible in recent years and is now recommended as first-line treatment for most women with significant perimenopausal symptoms.

Frequently Asked Questions

What age does perimenopause usually start?

Most commonly in the mid-to-late 40s, but it can begin in the late 30s. If you’re experiencing symptoms before 40, it’s worth getting a proper assessment as early menopause (before 40) is a distinct condition that needs specific management.

Do I need to fast before a hormone blood test?

No fasting is required for the hormone panels. For the Menopause and Wellbeing Screen, which includes cholesterol and glucose, we recommend fasting for 10 to 12 hours for the most accurate results.

What’s the best time in my cycle to test?

For women still having regular cycles, day 2 to 5 of the cycle (counting from the first day of your period) is the standard timing for FSH and oestradiol. If your cycles are irregular, testing at any point still gives useful information and your clinician can advise based on your specific situation.

Can I discuss HRT at Tamar Health?

Yes. Once you have your results, a consultation with one of our Advanced Practitioners can cover your options including HRT, and they can prescribe where clinically appropriate.

Is perimenopause different from early menopause?

Yes. Early menopause (also called premature ovarian insufficiency when it occurs before 40) is a separate condition. Perimenopause is the normal transitional phase that precedes menopause, typically in the mid-to-late 40s. If you’re under 40 with significant symptoms, it’s particularly important to get a proper clinical assessment.