Perimenopause and Menopause at Work

The transitional phase leading up to the final menstrual period, typically lasting 2-10 years. Defined by irregular cycles and fluctuating ovarian hormone output. Diagnosis is clinical – serum FSH is unreliable in this window.

The 12 months following the final menstrual period, or within 5 years of the final period (broadly). Vasomotor symptoms are typically at peak intensity. HRT initiation or optimisation is common in this window.

More than 5 years post final menstrual period, typically with stabilised or improving vasomotor symptoms. Long-term HRT users or those who have completed HRT are in this group. Bone health and cardiovascular risk become the primary clinical focus.

Ovarian insufficiency occurring before age 40, affecting approximately 1 in 100 women. May be idiopathic, autoimmune, genetic (e.g. Turner mosaic, FMR1 premutation), or iatrogenic. Distinct from natural menopause with significant additional health implications and often profound psychological impact.

Menopause induced by bilateral oophorectomy, typically as part of total hysterectomy or risk-reducing surgery (e.g. BRCA-related). Onset is abrupt rather than gradual, producing immediate and often severe vasomotor and hormonal symptoms without the transitional period of natural menopause.