Menopause is a natural occurrence. A woman's ovaries no longer release an egg every month, she stops having periods and she is no longer able to have children naturally. As the ovaries are the main source of female hormones (oestrogen, progesterone and testosterone), the levels of oestrogen, and progesterone hormones drop considerably with testosterone slowly declining with age affecting other parts of her body.

Menopause usually occurs between the ages of 48 and 55.

Among Australian women, the average age is about 51 to 52 years.

However, a few women experience menopause much earlier and others may still be menstruating in their late fifties. The age at which a woman goes through menopause is not influenced by race, height, the age that she experienced her first period, the number of children she has had, or whether she used the contraceptive pill as a method of birth control. However, cigarette smoking can influence the age at which a woman may go through menopause, with smokers and even former smokers reaching menopause an average of two years earlier.

As the average life span for Australian women, other than indigenous women, is now about 83 years and increasing, women are now living around one third of their lives after menopause.

Why Does Menopause Happen?

As a woman approaches menopause, hormone levels increasingly swing up and down and often, a woman notices changes in her menstrual cycle. For example:

• cycles may become longer, shorter or totally irregular;
• bleeding may become lighter; or
• bleeding may become unpredictable and heavy.

(Women with unpredictable or heavy bleeding should seek advice from their health practitioner as soon as possible).

Changes in hormone levels can also contribute to some of the symptoms that a women might experience at this time. This process can take up to four to six years on average in women.

Eventually, hormone levels will fall to a level where menstruation stops altogether and menopause is reached.

A woman needs to continue using contraception for a further 12 consecutive months after her last natural period.

Content updated July 3 2009