Osteopenia

Mild thinning of the bone mass, but not as severe as osteoporosis.

Osteopenia results when the formation of bone (osteoid synthesis) is not enough to offset normal bone loss (bone lysis).

Osteopenia is generally considered the first step along the road to osteoporosis, a serious condition in which bone density is extremely low and bones are porous and prone to shatter.

Diminished bone calcification, as seen on plain X-ray film, is referred to as osteopenia, whether or not osteoporosis is present.

The diagnosis of osteopenia may also be made by a special X-ray machine for bone density testing.

The World Health Organization (WHO) recognizes osteopenia, for people 50 and older with lower than average bone density who do not have osteoporosis.

WHO defines osteopenia as a bone density between one standard deviation (SD) and 2.5 SD below the bone density of a normal young adult.

(Osteoporosis is defined as 2.5 SD or more below that reference point.) 'Osteopenia' has two Greek ancestors: 'osteon', bone and 'penia', poverty = bone poverty.