Osteoporosis means bones becomes brittle and easy to break.

Osteoporosis is a silient disease, going undetected for many years until a fracture occurs.

The World Health Organization defines osteoporosis as a “ progressive systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture.” The low bone mass used to define osteoporosis is arbitrarily fixed at 2.5 standard deviations or more below the mean bone density for premenopausal women.

Definition useful for comparative purpose (AD Woolf, ASJ Dixon, Osteoporosis: A clinical Guide (2nd ed))

Osteoporosis : When the bone density measurement falls 2.5 or more standard deviations below the young adult mean for age and sex

Severe or established osteoporosis: Same Criteria as above but coupled with the presence of one or more fractures

Osteopenia (or low bone mass): When the bone density lies between 1 and 2.5 standard deviation below the mean for young adults.

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