The menopause refers to that time in every woman’s life when her periods stop and her ovaries lose their reproductive function. Usually, this occurs between the ages of 45 and 55, but in a few exceptional cases women may become menopausal in their 30s, or even younger. This is then known as a premature menopause, or premature ovarian insufficiency. The menopause is influenced by a change in hormone levels.
During a woman’s fertile years, her ability to produce an egg each month is associated with the release of three reproductive hormones (oestradiol, oestrone and oestriol), that are referred to collectively as oestrogen. Oestrogen is mainly produced by the ovaries, though small amounts are also made by the adrenal glands and by the placenta of a pregnant woman. It is oestrogen which stimulates female characteristics at puberty and controls a woman’s reproductive cycle: the development and release of an egg each month (ovulation) for implantation in the uterus (womb), and the way in which the lining of the uterus thickens to accept a fertilized egg.
The monthly period happens because no implantation has taken place – there is no pregnancy – and the lining of the uterus is shed. As women get older, their store of eggs in the ovary decreases and their ability to conceive diminishes. At this time, less oestrogen is produced, causing the body to behave differently. However, the body does not stop producing oestrogen overnight, and the process can even take several years, during which symptoms arise gradually. This gradual change is called the ‘peri-menopause’. At around the age of 50-55 years, the monthly cycle stops completely – so no more ovulations, no more periods and no more pregnancies. This is the menopause.