Menopause Clinical Features and Diagnosis
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Direct answer
Menopause is the permanent end of menstruation, confirmed retrospectively once a woman has had no periods for 12 consecutive months without another cause. It reflects exhaustion of ovarian follicles, with falling oestradiol and rising FSH. Because perimenopausal hormone levels swing widely, the diagnosis rests mainly on clinical criteria, and FSH is reserved for selected women.
What you must remember
- Definition: Twelve consecutive months of amenorrhoea without pregnancy, lactation or pathology; the date is set retrospectively from the last period.
- Premature ovarian insufficiency: Ovarian failure before 40 years, which needs its own evaluation and is separate from natural menopause.
- Early menopause: Final menses at about 40 to 45 years, a category distinct from premature insufficiency.
- Perimenopause: The transition from endocrine change and cycle irregularity until 12 months after the final period.
- Hormonal pattern: Oestradiol is variable early and falls late, FSH rises, and AMH falls as the ovarian reserve declines.
- Vasomotor symptoms: Hot flushes and night sweats, linked to a narrowed thermoneutral zone in the hypothalamus; they are the most common reason women seek care.
- Long-term effects: Accelerated bone loss, rising cardiovascular risk and genitourinary syndrome of menopause from oestrogen-dependent atrophy.
- Surgical menopause: Bilateral oophorectomy causes abrupt, symptomatic menopause whatever the woman's age.
A stepwise approach to diagnosing menopause
A 49-year-old woman with eight months of irregular periods and night sweats asks whether she has reached menopause. The steps below separate a true menopausal transition from its mimics.
- Confirm amenorrhoea: Menopause requires 12 months without bleeding, so irregular bleeding means perimenopause. Heavy or intermenstrual bleeding still needs assessment for endometrial pathology.
- Exclude mimics: Check pregnancy, thyroid function and serum prolactin, since thyroid disease and hyperprolactinaemia can both disturb cycles.
- Ask about contraception: Hormonal contraceptives, especially combined pills, suppress FSH, so a hormone result is misleading in these users.
- Use age to decide: In a woman over 45 with typical symptoms and irregular periods, clinical diagnosis is generally accepted without routine FSH.
- Test younger women twice: Under 45 with symptoms, measure FSH on two occasions several weeks apart; a persistently raised value, commonly above about 30 IU/L with amenorrhoea, supports ovarian failure.
- Refer if under 40: Premature ovarian insufficiency warrants karyotype and assessment for autoimmune and genetic causes, with bone and cardiovascular counselling.
Where the exam tries to catch you
Hormone tests and age cut-offs drive most of the traps here.
- Trap: Ordering an FSH level to confirm menopause in a woman on a combined oral contraceptive. Correct: The pill suppresses FSH, so the result is uninterpretable and the diagnosis should rest on clinical criteria.
- Trap: Treating one raised FSH value as proof of menopause in a 42-year-old. Correct: FSH swings from cycle to cycle, so repeated measurements are needed before ovarian insufficiency is labelled.
- Trap: Calling amenorrhoea at age 38 "natural menopause". Correct: Ovarian failure before 40 is premature ovarian insufficiency and needs karyotype testing and counselling.
- Trap: Assuming oestradiol is always low in perimenopause. Correct: Oestradiol can be normal or even high early in the transition, and falls only as follicles run out.
Frequently asked questions
Which hormone test is unreliable in a woman taking combined oral contraceptives for suspected menopause?
Serum FSH is unreliable in a woman taking combined oral contraceptives, because the oestrogen and progestogen suppress pituitary FSH release. The result then does not reflect ovarian reserve. Diagnosis should rest on clinical criteria, or testing should be deferred until the contraceptive is stopped.
How many months of amenorrhoea define menopause?
Menopause is defined by twelve consecutive months without a menstrual period, in the absence of pregnancy, lactation or another cause. The date is recorded retrospectively as the last menstrual period. A woman with irregular bleeding during that interval is still in perimenopause.
What is the age cut-off for premature ovarian insufficiency?
Premature ovarian insufficiency is ovarian failure before the age of 40 years. Early menopause, with final menses between about 40 and 45 years, is a separate category. Women with premature ovarian insufficiency need karyotype testing and counselling about bone and cardiovascular health.
Is FSH testing needed to confirm menopause in a woman over 45 with typical symptoms?
Generally no, because current guidance accepts a clinical diagnosis in women over 45 with typical symptoms and irregular periods. Routine FSH adds little in this group. Hormone testing matters more in women under 45, where ovarian insufficiency must be distinguished from other causes.
Which conditions must be excluded before diagnosing menopause?
Pregnancy, thyroid dysfunction and hyperprolactinaemia must be excluded before irregular or absent periods are attributed to menopause. Hormonal contraceptive use should also be documented, since it changes both bleeding and hormone levels. Once these are excluded, the clinical picture can be attributed to the menopausal transition.