摘要
骨质疏松症是一种系统性骨骼疾病，以骨量减少、骨微细结构破坏导致骨脆性增加、骨折危险性升高为特点。骨折可发生于椎体、前臂远端和股骨近端，在绝经后女性中尤为常见。以骨密度（BMD）这一概念为基础提出了骨质疏松症更为实用的定义。BMD低于正常青年人平均值的2．5 SD即可认为是骨质疏松症，如果患者发生骨质疏松相关性骨折亦可得到确诊。
Osteoporosis is a systemic skeletal disease characterized by low bone mass and micro-architectural deterioration, with a consequent increase in bone fragility and susceptibility to fracture. These fractures include the vertebral body, distal forearm and proximal femur, and are particularly common in postmenopausal women. A more practical definition of osteoporosis is based on bone mineral density （BMD）. BMD that is less than 2.5 standard deviations below the mean for young people may be considered osteoporosis, or established osteoporosis if the patient has sustained an osteoporosis-related fracture.
