Hormone replacement therapy is used to help balance estrogen and progesterone in women around the time of menopause.
Also known as hormone therapy (HT) or menopausal hormone therapy (MHT), hormone replacement therapy (HRT) can help relieve sweating, hot flashes, and other symptoms of menopause. It can also reduce the risk of osteoporosis.
Some types of HRT contain both progesterone and estrogen, some only estrogen, and sometimes testosterone is used.
Hormone replacement treatments are also used in male hormonal therapy and treatment for individuals who undergo a sex change.
This article focuses on HRT as a way of relieving symptoms in women around the time of menopause.
Fast facts on hormone replacement therapy (HRT)
Here are some key points about HRT. More detail is in the main article.
Hormone replacement therapy is an effective way to relieve symptoms of perimenopause and menopause.
It can reduce the incidence and severity of hot flashes, and also the risk of osteoporosis.
Past studies have suggested a link with cancer, but this is still being investigated.
It may help keep skin young, but it cannot reverse or delay the overall effects of aging.
Any woman who is considering HRT should talk to a physician who knows her medical history.
Menopause can bring discomfort and health risks, but HRT can help reduce these.
Progesterone and estrogen are important hormones in a woman’s reproductive system.
Estrogen stimulates the release of eggs, and progesterone prepares the womb for egg implantation.
As a natural part of the life process, the supply of eggs diminishes over time. As the number of eggs falls, so does estrogen production.
Most women will start to experience these changes in hormone levels during their late 40s. This can lead to hot flashes and other problems.
perimenopauseFor some time, a woman will continue to menstruate, although the changes are happening. This is called perimenopause. It can last from 3 to 10 years. Average duration is 4 years.
MenopauseWhen the last period occurs, at an average age of 51 years, the woman is in menopause.
Postmenopause: One full year after the last period, menopause ends, and the woman enters the postmenopausal stage. Symptoms normally decline within 2 to 5 years, but it can take 10 years or more.
The increased risk of osteoporosis continues after menopause.
Apart from the natural aging process, menopause can be triggered by a hysterectomy that includes removal of the ovaries, or cancer treatment.
Smoking can also speed up the arrival of menopause.
Effects of menopause
Changing hormone levels can cause severe discomfort and some health risks.
The following may occur:
bone thinning, or osteoporosis
hot flashes and night sweats
concentration and memory difficulties
smaller breasts and an accumulation of fat in the abdomen
HRT can bring some relief.
Does HRT cause cancer?
HRT was once widely used for reducing symptoms of menopause and protecting against osteoporosis and cardiovascular disease.
However, its benefits were questioned after two studies using data from the Women’s Health Initiative (WHI) were published, in 2002 and 2003. Findings linked HRT to endometrial, breast, and ovarian cancer.
This caused many people to rethink the use of HRT, and it became less widely used.
Now, further research has questioned those investigations. Critics point out that the findings were mixed, and since different hormone combinations can have different effects, the results did not really show how hazardous or how safe HRT might be.
In the case of breast cancer, a combination of progesterone and estrogen was linked to one extra case of breast cancer per year for every 1,000 women.
Newer studies have suggested that the benefits of HRT may outweigh the risks, but there is still some confusion.
A report published in The BMJ in 2012 concluded that “HRT may or may not increase the risk of breast cancer.”