The effect of hormonal changes on the body
During menopause, the normal number of follicles in the ovaries drops suddenly and dramatically, which brings on menstrual irregularities. Ovarian functioning also declines, as does the amount of the female hormone estrogen secreted.
The hormonal imbalance caused by the sudden drop in estrogen secretion brings about a variety of physical and psychological symptoms. The menstrual cycle first becomes irregular and eventually ends.