Perimenopause, or the menopausal transition, is the time leading up to your last period. Perimenopause means “around menopause.”
Perimenopause is a long transition to menopause or the time when your periods stop permanently and you can no longer get pregnant.
As your body transitions to menopause, your hormone levels may change randomly, causing menopause symptoms unexpectedly.
During this transition, your ovaries make different amounts of the hormones estrogen and progesterone than usual.
Source: MedlinePlus, National Library of Medicine