Hormone Testing at 40+: What It Can and Cannot Tell You

Women arriving with hot flushes, broken sleep, mood changes and irregular periods often expect a blood test to settle the question. Sometimes it helps. Often it cannot, and knowing which situation you are in saves both money and frustration.

The difficulty is that perimenopausal hormones fluctuate enormously — not only month to month but week to week. A single FSH or estradiol reading is a snapshot of a moving target, and a normal result on a day when levels happen to be normal does not rule out perimenopause. This is why guidelines generally say the diagnosis in women over 45 is made on symptoms and cycle pattern, not on blood tests.

Where testing genuinely earns its place: under 40, where premature ovarian insufficiency needs excluding and the result changes management substantially; between 40 and 45, where it can add useful information; when symptoms could plausibly be something else, particularly thyroid disease or anaemia, both of which cause fatigue and mood change and are entirely treatable; and when a specific decision depends on it.

What is more useful than most people expect is a symptom and cycle record. Dates of recent periods, what changed and when, sleep, and how symptoms track across the month tell a clinician more than one reading taken on an arbitrary day.

It is also worth separating the symptoms that are hormonal from those that are not. Vaginal dryness, urinary urgency and discomfort during sex are all commonly hormonal and commonly treatable — and often not mentioned, because women assume they are separate problems or not worth raising.

See a doctor if periods stop before 45, if bleeding is heavy or between periods, if symptoms are disrupting work or sleep, or if you want to discuss options — including non-hormonal ones. Suitability is decided individually after assessment.