Hormone replacement therapy (HRT)

Hormone replacement therapy (HRT) is a treatment used to replace hormones that your body is no longer producing because of the menopause. The hormones that need replacing are oestrogen and progesterone.

The menopause is triggered when your ovaries are no longer producing eggs. Each woman has an individual, set number of eggs. One or more eggs is released every month when you have your period.

The average age for women to experience the menopause is 52. Some women may experience the menopause when they're still in their forties.

Early menopause is when a woman goes through the menopause in her thirties or even twenties, but this is rare.

The role of oestrogen

Oestrogen is used by your body to stimulate the release of eggs. Once there are no eggs to release, the level of oestrogen in your body will begin to fall.

However, oestrogen also helps regulate many other bodily functions, including bone density, the temperature of your skin and keeping the vagina moist.

It is the reduction of oestrogen that causes most of the symptoms associated with the menopause.

These include:

• hot flushes,
• vaginal dryness,
• loss of sex drive,
• mood changes,
• stress incontinence (leaking urine when you cough or sneeze),
• night sweats,
• thinning of the bone, which can lead to brittle bones (osteoporosis),

Most of these symptoms pass within two to five years, though vaginal dryness is likely to worsen if it is not treated. The risk of osteoporosis also increases with age.

The role of progesterone

The main function of progesterone is to get the womb ready for a possible pregnancy. It also helps to protect the lining of the womb (endometrium).

The falling levels of progesterone don't have the same wide-ranging effects on your body as the falling levels of oestrogen. However, it does increase your risk of developing cancer of the womb lining (endometrial cancer).

This is why progesterone is used in combination with oestrogen. (Women who've had a hysterectomy don't require progesterone and can take oestrogen-only HRT.)

Benefits and risks

HRT is one of the most extensively studied medical treatments and a great deal of information is known about both the benefits and risks of HRT.

The main and most obvious benefit of HRT is that it has proved very successful in controlling the symptoms of the menopause. The difference this can make to a woman's quality of life and well-being should not be underestimated.

It can also reduce your risk of developing osteoporosis and cancer of the colon and rectum. However, the long-term use of HRT to prevent osteoporosis is not usually recommended. This is because there are other medicines available that don't carry the same level of associated risk.

There is a risk that HRT slightly raises the chance of developing certain conditions, such as breast cancer, endometrial cancer, ovarian cancer and stroke.

Most experts agree that if HRT is used on a short-term basis (no more than five years) then the benefits of it outweigh any associated risk.

If it's taken for longer, especially for more than 10 years, you should discuss your individual risks with your GP and review these risks on a yearly basis.