The phase of a woman’s life before the onset of menopause when menstruation stops. The average age for the onset of perimenopause is late 40s to early 50s. This stage can last a few months (if you’re lucky) or continue for up to 10 years as periods become irregular and estrogen levels drop. Symptoms are hot flashes, breast tenderness, worse premenstrual syndrome (PMS), lower sex drive, mood swings, vaginal dryness, and more. Fun, right?