Your doctor may think you have osteoporosis just from talking to you and examining you. But you will probably need a scan to say for sure.

Here are some of the things that may make your doctor think you have osteoporosis.

• You broke a bone very easily, especially one in your spine, hip, or wrist.

• You are a woman who has been through the menopause and you are getting shorter or your spine is curving forward.

• You have lots of risk factors (things that make it more likely that you will get osteoporosis). For example, you are a woman who has been through the menopause, and your mother had osteoporosis, and you have small bones and you weigh less than 40 kilograms (88 pounds).^[45]

If your doctor thinks you have osteoporosis, he or she will want to measure your bone mineral density. This is called BMD for short. It tells your doctor how much calcium and other minerals you have packed in your bones. The more you have, the stronger (denser) your bones are.

DXA scans and other scans

The most common type of scan to measure your BMD is called a DXA scan. That's short for dual-energy x-ray absorptiometry.

You may need to go to hospital for this scan. But you will go home the same day. You may have to put on a hospital gown. But in some hospitals, you can keep your own clothes on.

For this scan, you just lie on a table while the machine moves over your body. It won't touch you and you won't feel anything. The scan takes just five minutes to ten minutes. It uses radiation to measure how strong your bones are. But you get less radiation from a DXA scan than you do from a regular x-ray.

This scan is the most reliable one for saying if you have osteoporosis. And it is the best test for measuring BMD.^[46]

There are other, smaller scanning machines. These measure the BMD in your smaller bones, like the ones in your fingers, wrists, or heels. These scans aren't as reliable as a DXA scan. You may have these first if your hospital doesn't have a DXA scanner. For more, see Other scans to measure BMD.

Tests of your BMD can't say for sure if you will break a bone or not. They can only say how strong or weak your bones are. You may never break a bone, even if your bones are weak. And you can still break a bone even if your bones are strong. Experts think that only half of all fractures caused by osteoporosis could be predicted by DXA scans.^[47]

Who should have a DXA scan?

In the UK, experts say you should have a DXA scan only if your doctor thinks you are more likely than average to get osteoporosis.^[48]

Doctors agree that you should also have a DXA scan if:^[48]

• You have already broken a bone after a small bump or fall

• You take corticosteroid tablets regularly (this can make your bones weak)

• You are a woman who had the menopause before the age of 45 or had your ovaries taken out before the age of 45

• You are a woman who has missed menstrual periods (except when you were pregnant or after the menopause) for more than a year (this could happen because of anorexia or bulimia, or exercising too much)

• You are a man who has low levels of a hormone called testosterone

• You have other conditions that cause weak bones (these include conditions called malabsorption syndrome and hyperparathyroidism)

• You have had to stay in bed for a long time

• You are a woman and your mother broke her hip.