Your doctor will usually be able to tell if you are going through the menopause from symptoms like hot flushes and night sweats.
Strictly speaking, the menopause is the time when your periods stop. Most doctors say you have definitely reached the menopause when you've had no periods for a year.
But you can get symptoms of the menopause long before your periods stop. This is because the changes in your body that lead to the menopause start much earlier, even as early as 10 years before your last period. If your symptoms are bothering you, it's worth seeing your doctor even if your periods haven't finished.
Your doctor will carefully consider the symptoms you are having. He or she may ask you questions about your symptoms to make sure that there's nothing else that could be causing them. And, of course, your doctor will consider your age. Most women begin the lead up to the menopause (which is called the perimenopause) between the ages of 45 and 47.
Here are some of the things your doctor may ask.
Have your monthly periods changed? For example, how long is it since you had a period? Are you having your period more often or less often than you used to? Has the bleeding got heavier or lighter?
Are you having any symptoms of the menopause? For example, does your vagina feel dry or have you had urinary tract infections?
Are you having hot flushes or waking up at night sweating?
If there's doubt about whether your symptoms could be caused by the menopause (for example, if you're younger than 40), then your doctor may want to do a blood test called the FSH test.
The FSH test
One of the ways doctors can tell if you are nearing the menopause is by doing an FSH test. They usually do it if they think your symptoms may be due to something other than the menopause.
This test measures the levels of a chemical called follicle-stimulating hormone (FSH) in your blood. When your oestrogen levels start to drop, the pituitary gland in your brain releases more FSH to try to get your ovaries to make oestrogen. For more about FSH see What happens every month.
So, if your levels of FSH are rising, you could be going through the menopause. But if you are taking the contraceptive pill, the FSH test won't work, because the pill affects your hormones.
Doctors don't normally rely on the FSH test to tell if you have reached the menopause. They can often tell just from your symptoms.