Menopause is a natural change that a woman's body goes through during the aging process.  It is defined as the permanent end of menstruation and signals the end of her reproductive years.  After this time, a woman will no longer ovulate (produce an egg).    It is difficult to determine the exact time that menopause has begun, because it does not occur as a single event. As such, it is usually diagnosed in retrospective, after one year without any menstrual periods. It usually occurs between 45-55 years of age.  It is accompanied by hormonal changes that can have a profound effect on a woman's body and in her life. 

As a woman ages her ovaries begin to gradually lose function.  Egg production decreases,  and the female sex hormones produced by the ovaries, estrogen and progesterone, decline gradually.  This hormonal fluctuation and imbalance results in the appearance of menopausal symptoms over time, including changes in menstrual cycle/irregular cycle  and bleeding, hot flashes, night sweats, insomnia, headaches, decreased sex drive, vaginal dryness and thinning, depression, moodiness/ mood swings, tiredness, decreased energy level, hair thinning/loss, etc.  In addition, there are increased health risks.  The risk of heart disease and osteoporosis (thinning of the bone) rise significantly.    

Many women experience hormonal fluctuations and menopausal symptoms before menopause actually occurs.  This time frame, when irregular periods occur but before the  actual onset of menopause, is called peri-menopause.  Some women skip this phase entirely.  In others, it can last anywhere from a few months up to ten years before menopause.