Hormones . Symptoms guide
Perimenopause: Symptoms and When to Test
Perimenopause is the years-long hormonal transition before menopause. Symptoms can begin in the late 30s and often overlap with thyroid disease, iron deficiency and stress. Blood testing for FSH, LH, oestrogen, thyroid function and ferritin distinguishes perimenopause from its mimics and informs whether HRT or other treatment is appropriate.
This patient information is being clinically reviewed by our team. The factual content draws on UK guidance (NHS, NICE, British Association of Dermatologists, British Society for Sexual Medicine where cited).
What this might be
- Perimenopausal hormonal change. Falling and fluctuating oestrogen, rising FSH.
- Thyroid dysfunction. Symptoms overlap heavily with perimenopause; always worth checking together.
- Iron deficiency. Heavier or irregular periods deplete iron stores.
- Vitamin D deficiency. Common in women with perimenopausal mood and bone changes.
Common features that suggest this
- Irregular periods or cycle length changes
- Hot flushes or night sweats
- Sleep disruption
- Mood changes, anxiety, or low mood
- Brain fog or difficulty concentrating
- Hair thinning or skin changes
- Joint pain
Recommended tests
Same-day appointments at our Harley Street clinic, results clinician-reviewed.
Need a marker not in these panels? Build a custom panel and a GMC-registered clinician will design one for you.
Testing advice
Days 2 to 5 of the menstrual cycle give the most useful baseline if cycles are still regular. If cycles are irregular or absent, any day is acceptable. Morning slot recommended.
Common questions
Can a single test confirm perimenopause?
Not always. Hormone levels fluctuate during this period, which is part of the diagnostic picture. Symptoms and history matter as much as the numbers. Our clinicians interpret bloodwork in context.
Will the test tell me when menopause is coming?
No test predicts the timing precisely. FSH trends rising and oestrogen falling suggest progression; cycle changes are usually the better indicator.
Do I need HRT?
That is an individual decision based on symptom severity, bloodwork and personal risk profile. Bloodwork is the first step, not the answer.
Related symptoms
Sources and further reading
This page provides general information only and is not a substitute for medical advice. A GMC-registered clinician will review your results and tailor any recommendations to you personally.