Menopause is effectively the end of the female menstrual cycle, when you stop getting your period. It usually happens around the age of 45 but the changes associated with menopause can start several years before you have your last period, including changes in the frequency and nature of your bleeding. Menopause is a result of a change in your hormones, which can lead to weight gain, sleeplessness, hot flashes, mood swings, and headaches.