During this time of shutdown, the body is continually trying to adapt to the changing level of hormones which is the cause of the symptoms we commonly know: - Increased depression - Anxiety - Irritability - Mood swings - Lack of concentrationIt isn't uncommon for a woman to have increasingly scanty and random menstrual periods along with the above symptoms. The typical time for this cycle is about one year, but can swing to as little as 6 months, and to as great as 5 years in extreme cases. is part of a normal aging process, and on average occurs as 50.There is several different factors which can attribute the timeline of menopause. An example of such is: both fraternal and identical twins will on average reach menopause before other women; approximately five percent of twins will reach menopause before they turn forty. There is no way to predict in advance how long, or when menopause will exist, but if you spend some time going over it with your doctor you will be able to have a better idea.