Perimenopause
The transition phase leading up to menopause.
Can last several years.
Periods may become irregular.
Symptoms like hot flashes and mood changes may begin.
Menopause
The point when a woman has not had a period for 12 months in a row.
Ovaries stop releasing eggs.
Hormone levels remain low.
Postmenopause
The years after menopause
Menopausal symptoms may ease but health risks related to lower estrogen (like osteoporosis or heart disease) can increase.