How is osteoporosis diagnosed?
There are no clear physical signs of osteoporosis and it may not cause any problems for some time. If your doctor thinks you may have osteoporosis, they may suggest you have a DEXA (dual energy x-ray absorptiometry) scan to measure the density of your bones.
The scan is readily available and involves lying on a couch, fully clothed, for about 15 minutes while your bones are x-rayed. The dose of x-rays is very small – about the same as spending a day out in the sun. The possible results are:
Normal – Your risk of a low-impact fracture is likely to be low.
Osteopenia – Your bone is becoming weaker but your risk of a low-impact fracture is relatively small. You may or may not need treatment depending on what other risk factors you have. You should discuss with your doctor how you can reduce your risk factors.
Osteoporosis – You have a greater risk of low-impact fractures and you may need treatment. You should discuss this with your doctor.
Who should have a scan?
There's no good evidence that screening everybody for osteoporosis would be helpful. However, you should talk to your doctor about having a scan if any of the following apply to you:
- you’ve already had a low-impact fracture
- you need steroid treatments for 3 months or more
- you had an early menopause (before the age of 45)
- either of your parents has had a hip fracture
- you have another condition which can affect the bones – for example, coeliac disease, inflammatory bowel disease (Crohn’s disease or ulcerative colitis), rheumatoid arthritis, diabetes and hyperthyroidism (overactive thyroid)
- you have a body mass index (BMI) of less than 19.
How to work out your body mass index:
- Multiply your height in metres by itself – e.g. 1.7 (m) x 1.7 = 2.89
- Divide your weight in kilograms (kg) by the number you got in stage 1 – e.g. 53 (kg) ÷ 2.89 = 18.3
- The result is your BMI e.g. 18.3
For most people a healthy BMI is between 19 and 25.
Your doctor may use an online scoring tool called FRAX®, developed by the World Health Organization (WHO), to help assess your risk of fracture and to help decide whether you should have a DEXA scan or treatment for osteoporosis.