Pre menopause - This is the stage where a woman has no symptoms of perimenopause or menopause. She will still have periods and is medically considered to be in her reproductive years.
Perimenopause - As a woman gets closer to her 40s, her periods may become irregular (heavier/lighter, more spaced out), and her hormones (estrogen, progesterone and testosterone) are dropping in an irregular way, and you may notice changes in your physical, mental, and emotional health – these are common signs you’re entering perimenopause which last for 7-10 years.
Menopause - Menopause is defined as the period of time when a woman has not had a period for 12 months.
Post menopause - This is the period of time after a woman has not had a menstrual period for an entire year, and is the rest of her life after going through menopause.