Menopause is the complete shutting down of the female reproductive system. The word literally means the permanent physiological, or natural, cessation of menstrual cycles, from the Greek roots 'meno' (month) and 'pausis' (cessation). In other words, menopause is the natural and permanent stopping of the monthly female reproductive cycles, and in human females who still have a uterus, this is traditionally indicated by a permanent absence of monthly periods or menstruation.

The word is most commonly used in regard to human females, where menopause happens more or less in midlife, signaling the end of the fertile phase of a woman's life. Menopause is perhaps most easily understood as the opposite process to menarche.

Menopause in women cannot be defined simply as the permanent "stopping of the monthly periods", because in reality what is happening to the uterus is quite secondary to the process. For medical reasons, the uterus is sometimes surgically removed (hysterectomy) in a younger woman, and after this her periods will cease permanently, and the woman will technically be infertile, but as long as at least one of her ovaries is still functioning, the woman will not have entered menopause. This is because even without the uterus, still, ovulation and the release of the sequence of reproductive hormones that are an essential part of the reproductive cycles, will continue until the time of menopause is reached.

Menopause is triggered by the faltering, shutting down, or surgical removal of the ovaries, which are a part of the body's endocrine system of hormone production, in this case the hormones which make reproduction possible and influence sexual behavior.

The process of the ovaries shutting down is a phenomenon which involves the entire cascade of a woman's reproductive functioning, from brain to skin, and this major physiological event usually has some effect on almost every aspect of a woman's body and life.

It is worth pointing out however that the menopause transition, and post-menopause itself, is a natural life change, not a disease state or a disorder. The transition itself can be challenging for a number of women, but for others it is not difficult.