Page "Menopause" Paragraph 18

On average, assuming there has been no surgical intervention, the first evidence of the onset of the menopause transition time is slight variations in the length of the menstrual cycle.

These variations become more pronounced over time, and eventually lead to cycles that can be considerably longer or considerably shorter than usual, flow that can be significantly lighter or heavier than usual, skipped ovulations, skipped periods, and spans of time of many months with no flow at all, after which menstruation may resume.

The transition is considered to be over once a woman has experienced 12 months without any menstrual bleeding at all, even though perimenopause effects may extend well beyond this point in time.

The term " perimenopause ", which literally means " around the menopause ", refers to the menopause transition years, a span of time both before and after the date of the final episode of flow.