**2. Definition**

Natural menopause is recognized to have occurred after 12 consecutive months of amenorrhea, for which there is no other obvious pathological or physiological cause. Menopause occurs with the final menstrual period, which is known with certainty only in retrospect a year or more after the event. An adequate independent biological marker for the event does not exist.

The term "perimenopause" should include the time immediately prior to the menopause (when the endocrinological, biological, and clinical features approaching menopause commence) and the first year after menopause.

The term "menopausal transition" should be reserved for the time before the final menstrual period when variability in the menstrual cycle is usually increased. This term can be used synonymously with "premenopausal."

Relationship between different time periods surrounding the menopause (modified from the WHO 96238) is shown in the table below.


**FMP**
