Peri-menopause is the time period before menopause when hormonal fluctuations are common. Peri-menopause can last as long as 10 years; during this time, menstrual cycles may change in length, frequency, duration and intensity. During peri-menopause, ovulation may not occur every month; according to Gerson Weiss, M.D.

Perimenopause is the transitional period women undergo between fertility and menopause. Hormone levels fluctuate, according to the Mayo Clinic, and you often begin to experience many of the signs and symptoms associated with menopause.