Osteoporosis and bone density tests
A bone density test is a special X-ray scan that may be recommended for people at a higher risk of developing osteoporosis.
Knowing the density and strength of a person's bones can help doctors make decisions on steps to help prevent osteoporosis or the risk of falls and bone fractures.
The bone density scan used by the NHS is DEXA, or dual energy X-ray absorptiometry.
Who should have a bone density test?
Your GP will take a medical history to help decide whether a bone density scan might be appropriate for you. The following factors may be discussed to assess your risk of osteoporosis:
- History of previous fractures or falls
- Age is particularly relevant if you are post- menopausal
- Maternal history of osteoporosis or fracture
- Ethnicity - white people have a higher risk of osteoporosis than other ethnic groups
- Medical conditions: certain diseases increase your risk of fractures and bone loss such as rheumatoid arthritis, and problems with food nutrient absorption such as coeliac disease
- Heavy smoking and alcohol consumption
- Long periods of inactivity
- Low body mass index (BMI)
- Inadequate diet
After taking a history the GP will normally decide whether a bone scan would be appropriate for you.
Having a DEXA scan
The DEXA scan takes up to around 20 minutes and is not painful. During the test, the patient lies down while a scanner passes over them.
The DEXA scanner produces a T score for bone density, comparing the person's bones with the bones of a healthy person of around the same age.
- A T score of between +1 and -1 is classed as normal.
- A T score between -1 and -2.5 indicates osteopenia, an early form of osteoporosis.
- A T score below -2.5 suggests the person has osteoporosis.