Perimenopause, the beginning of the transition to menopause, can begin when a woman is in her late 30s but is most dominant in women over 40, explains Marla Ahlgrimm. This is a transitional period before menopause. According to Marla Ahlgrimm, symptoms of perimenopause may include irregular or heavy periods and vaginal dryness. Perimenopausal women may also experience difficulty sleeping, mood swings and fatigue. It is not uncommon to experience hot flushes similar to those in menopause and breast tenderness much like early pregnancy, says Marla Ahlgrimm.