Menopause: What and when is Menopause?
Menopause- what happens?
All women will experience the menopause. Natural menopause takes place when the ovaries become unable to produce the hormones estrogen and progesterone. Menopause can also occur when the ovaries are damaged by specific treatment such as chemotherapy or radiotherapy, or when the ovaries are removed, often at the time of a hysterectomy. Ovaries naturally fail to produce estrogen and progesterone when they have few remaining egg cells; the maximum number of egg cells in the ovaries is present before birth, with a reduced number already at birth, gradual reduction from puberty, and a rapid decline from 40 onwards. With less egg cells, the ovaries become less able to respond to hormones from the pituitary gland in the brain: follicle stimulating hormone (FSH) and luteinising hormone (LH) and less estrogen is produced. Levels of FSH and LH subsequently rise and a measurement of FSH is sometimes used to diagnose menopause. The resulting low, and changing levels of ovarian hormones, particularly estrogen, are thought to be the cause of menopausal symptoms and later consequences in many women.
The term climacteric refers to the time in which the hormone levels are changing, up to the periods stopping; reducing and changing hormone levels can cause early menopausal symptoms. At this stage, there may still be enough hormones produced to stimulate the lining of the womb (endometrium) to produce monthly periods (menstruation).
Menopause means the last menstrual period. Periods stop because the low levels of estrogen and progesterone do not stimulate the lining of the womb (endometrium) in the normal cycle. Hormone levels can fluctuate for several years before eventually becoming so low that the endometrium stays thin and does not bleed.
Perimenopause is the stage from the beginning of menopausal symptoms to
See our magazine article: Perils of the Perimenopause. PDF (115Kb)
Postmenopause is the time following the last period, and is usually defined as more than 12 months with no periods in someone with intact ovaries, or immediately following surgery if the ovaries have been removed.
Menopause - when?
The average age of the natural menopause is 51 years, but can
occur much earlier or later. Menopause occurring before the age of
45 is called early menopause and before the age of 40 is premature
Generally, women having an early or premature menopause are advised to take HRT until approximately the average age of the menopause, for both symptom control and bone protective effect.
Late menopause may also occur but by the age of 54, 80% of women will have stopped having periods.
|Download the Advice to Patients leaflet:
What is the Menopause
pdf file, 5 pages, 69K updated 9 April 2019