Menopause & perimenopause

Menopause is the permanent end of menstruation caused by the ovaries running out of responsive follicles. As the follicle pool falls, estradiol production becomes erratic then low, and the pituitary pushes FSH up trying to stimulate ovaries that no longer respond — so a high FSH with a low estradiol is the hormonal signature. It is a clinical diagnosis: 12 consecutive months without a period, typically between 45 and 55 (average 51). The years leading up to it — perimenopause — feature fluctuating hormones, shortening then lengthening cycles, and most of the symptoms. Menopause before 40 is 'primary ovarian insufficiency' and is investigated differently. Beyond symptoms, the estrogen fall accelerates bone loss (osteoporosis risk) and removes a cardiovascular-protective effect.

• FSH — rises as ovaries stop responding; a persistently high FSH supports menopause, though it fluctuates during perimenopause.
• Estradiol — falls; high FSH + low estradiol is the classic pattern.
• LH — also rises.
• TSH — checked because thyroid disease mimics menopausal symptoms (fatigue, weight and mood change, irregular periods).
• Prolactin — excludes another cause of missed periods.
• Lipids, glucose/HbA1c, vitamin D — baseline for the rising cardiometabolic and bone risk after menopause. In a woman over 45 with typical symptoms, menopause is diagnosed clinically — hormone tests are often unnecessary.

• Irregular then absent periods
• Hot flushes and night sweats
• Sleep disturbance, fatigue
• Mood changes, anxiety, low mood, irritability
• Brain fog, difficulty concentrating
• Vaginal dryness, discomfort with sex, urinary urgency
• Reduced libido
• Joint aches
• Longer term: accelerated bone loss, rising cardiovascular risk