When a woman reaches her early forties, there are fewer ovarian follicles left in the ovaries. As a result, ovulation occurs less frequently. Because the follicles produce much of the estrogen in the body, estrogen levels also begin to decline.
Perimenopause is the term used to describe the period between a woman's reproductive years and and the time when menstruation ceases completely. During that time, hormone levels fluctuate and decline, often at an irregular pace. The hormonal shifts contribute substantially to the sense of physical, mental and emotional imbalance that may characterize a woman's experience of menopause.
Menopause is the term that represents the end of menstruation. Estrogen levels eventually decrease to the point where buildup of the uterus lining no longer occurs, resulting in cessation of menstruation and onset of menopause. The majority of women experience natural menopause between the ages of 45 and 55. However, the onset of menopause can occur as early as in a woman's 30's and as late as her 60's.
Menopause is a natural event, not a disease.
Menopause, although a natural part of a woman's life, is very often accompanied by such uncomfortable side effects, as well as significant health issues such as cardiovascular diseases and bone loss, which can lead to osteoporosis.