Perimenopause, also called menopausal transition, is the time near the end of reproductive years. This period starts from mid 30s to early 40s. In this period, the menstrual cycles are irregular with varying length and flow. Sometimes, the menstruation occurs without ovulation. Relevant signs and symptoms include those of menopause such as hot flashes, mood swings, sleep disturbances and vaginal dryness. When there is no menstruation for 12 months in a row the perimenopause ends and menopause is achieved.