Bone mineral density may be quoted as the number of standard deviations(SD) from the young adult mean. This is known as the T score.
The World Health Organisation define normal bone density to be within 1 SD of the young adult mean i.e. T score > -1. Osteopenia is defined by a T score between -1 and -2.5. Osteoporosis is defined as a T score less than -2.5.
It should be noted that the WHO definition of osteoporosis encompasses a large proportion of the elderly population and as mentioned elsewhere it is not the only consideration in determining treatment.
Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page