Several osteoporotic fractures such as hip fractures have a very high morbidity and mortality, and there are similar new findings for vertebral fractures. There have been several definitions of an osteoporotic fracture, and recently updated definitions have specified fractures occurring at a site associated with low BMD and which increase in incidence after the age of 50 years. Other definitions are based on clinical diagnosis. Lifetime risk of any osteoporotic fracture is very high and lies within the range of 40-50% in women and 13-22% for men. Measuring the true burden of osteoporotic fractures involves multiplying the morbidity of hip fractures according to age group: for women aged 50-54 years, the disability caused by osteoporotic fractures is 6.07 times that accounted for by hip fracture alone, and for women aged 80-84 years, the incidence of hip fractures should be multiplied by 1.55; for men aged 50-54 years, the incidence of hip fractures should be multiplied by 4.48, and for those aged 80-84 years by 1.50.