How do I know if I'm going through perimenopause or menopause?

Menopause is defined as the period in a woman's life when she has not experienced a menstrual cycle for 12 consecutive months, provided there are no medications or medical conditions affecting her periods (for example, an IUD, thyroid disease, very low body weight, etc). Typically, menopause occurs between ages 45 and 59. Prior to reaching menopause, women may go through a phase known as perimenopause.

Perimenopause is the transitional period leading up to menopause, characterized by hormonal changes and physical symptoms as the ovaries gradually reduce estrogen production. During this time it is common to experience dramatic fluctuations in estrogen hormone levels which can cause symptoms such as hot flashes, night sweats, mood changes, irregular bleeding, metabolic changes, insomnia, increased anxiety or depression and cognitive difficulties.  This phase typically begins 3-7 years before menopause. Various physical changes to the skin, hair, breasts, and vulvovaginal tissues also occur during menopause and perimenopause.