The menopause is when a woman stops having periods and is no longer able to get pregnant naturally.
Periods usually start to become less frequent over a few months or years before they stop altogether. Sometimes they can stop suddenly.
The menopause is a natural part of ageing that usually occurs between 45 and 55 years of age, as a woman's oestrogen levels decline. In the UK, the average age for a woman to reach the menopause is 51.
But around 1 in 100 women experience the menopause before 40 years of age. This is known as premature menopause or premature ovarian insufficiency.
Most women will experience menopausal symptoms. Some of these can be quite severe and have a significant impact on your everyday activities.
Common symptoms include:
Menopausal symptoms can begin months or even years before your periods stop and last around 4 years after your last period, although some women experience them for much longer.
It's worth talking to a GP if you have menopausal symptoms that are troubling you or if you're experiencing symptoms of the menopause before 45 years of age.
They can usually confirm whether you're menopausal based on your symptoms, but a blood test to measure your hormone levels may be carried out if you're under 45.
Your GP can offer treatments and suggest lifestyle changes if you have severe menopausal symptoms that interfere with your day-to-day life.
These include:
Your GP may refer you to a menopause specialist if your symptoms do not improve after trying treatment or if you're unable to take HRT.
The menopause is caused by a change in the balance of the body's sex hormones, which occurs as you get older.
It happens when your ovaries stop producing as much of the hormone oestrogen and no longer release an egg each month.
Premature or early menopause can occur at any age, and in many cases there's no clear cause.
Sometimes it's caused by a treatment such as surgery to remove the ovaries (oophorectomy), some breast cancer treatments, chemotherapy or radiotherapy, or it can be brought on by an underlying medical condition, such as Down's syndrome or Addison's disease.
Most women will experience some symptoms around the menopause. The duration and severity of these symptoms varies from woman to woman.
Symptoms usually start a few months or years before your periods stop, known as the perimenopause, and can persist for some time afterwards.
On average, most symptoms last around 4 years from your last period. However, around 1 in every 10 women experience them for up to 12 years.
If you experience the menopause suddenly rather than gradually – for example, as a result of cancer treatment – your symptoms may be worse.
The first sign of the menopause is usually a change in the normal pattern of your periods.
You may start having either unusually light or heavy periods.
The frequency of your periods may also be affected. You may have them every 2 or 3 weeks, or you may not have them for months at a time.
Eventually, you'll stop having periods altogether.
About 8 in every 10 women will have additional symptoms for some time before and after their periods stop.
These can have a significant impact on daily life for some women.
Common symptoms include:
The menopause can also increase your risk of developing certain other problems, such as weak bones (osteoporosis).
See your GP if you're finding your symptoms particularly troublesome, as treatments are available.
Not all women want treatment to relieve symptoms of the menopause, but treatments are available if you find the symptoms particularly troublesome.
The main treatment for menopausal symptoms is hormone replacement therapy (HRT), although other treatments are also available for some of the symptoms.
HRT involves taking oestrogen to replace the decline in your body's own levels around the time of the menopause. This can relieve many of the associated symptoms.
Guidelines from the National Institute for Health and Care Excellence (NICE) say that HRT is effective and should be offered to women with menopausal symptoms, after discussing the risks and benefits.
There are two main types of HRT:
HRT is available as tablets, skin patches, a gel to rub into the skin or implants.
HRT is extremely effective at relieving menopausal symptoms, especially hot flushes and night sweats, but there are a number of side effects, including breast tenderness, headaches and vaginal bleeding. It's also associated with an increased risk of blood clots and breast cancer in some women.
HRT is not advisable for some women, such as those who have had certain types of breast cancer or are at high risk of getting breast cancer.
Your GP can give you more information about the risks and benefits of HRT to help you decide whether or not you want to take it.