The menopause, sometimes referred to as the "change of life", is the end of menstruation.
This is where a woman's ovaries stop producing an egg every four weeks. She no longer has monthly periods and is unlikely to get pregnant.
In the UK, 51 is the average age for a woman to reach the menopause, although some women experience the menopause in their 30s or 40s.
If you experience the menopause before the age of 40, it's known as a premature menopause.
Menstruation (monthly periods) can sometimes stop suddenly when you reach the menopause. However, it's more likely that your periods will become less frequent, with longer intervals between each one, before they stop altogether.
What causes the menopause?
The menopause is caused by a change in the balance of the body's sex hormones.
In the lead-up to the menopause, known as the perimenopause, oestrogen levels decrease, causing the ovaries to stop producing an egg each month (ovulation). Oestrogen is the female sex hormone that regulates a woman's periods.
Read more about what causes the menopause.
The reduction in oestrogen causes physical and emotional symptoms, including:
Read more about the symptoms of the menopause.
When to see your GP
You should see your GP if you have menopausal symptoms that are troubling you.
In women under 50 years of age, the menopause is diagnosed after 24 months without a period. In women aged 50 or over, it's diagnosed after 12 months without a period.
There's no definitive test to diagnose the menopause. A blood test is sometimes carried out to measure the level of the follicle-stimulating hormone (FSH). However, the result only occasionally helps in managing the menopause.
Treating the menopause
Medication isn't always needed to treat oestrogen deficiency symptoms that can occur around the time of the menopause. Many women find that making simple diet and lifestyle changes can help relieve their symptoms (see below).
Treatment may be recommended if you have more severe menopausal symptoms that interfere with your day-to-day life.
Hormone replacement therapy (HRT) is one of the main treatments used for the menopause. It helps relieve menopausal symptoms by replacing oestrogen. It's available in many forms including tablets, cream or gel, a skin patch or an implant.
Vaginal lubricants can be used to treat vaginal dryness, and antidepressants are sometimes prescribed for treating hot flushes.
Read more about treating the menopause.
Making simple dietary and lifestyle changes can often improve your menopausal symptoms.
For example, eating a healthy, balanced diet and taking plenty of regular exercise can help you avoid putting on extra weight, which can often occur during the menopause.
A healthy diet that includes all the food groups will help keep your bones strong and healthy. Combining aerobic activities, such as walking, with strength and flexibility exercises will also help you maintain bone strength and muscle mass.
Read more self-help tips for managing the menopause.