There are two definitions of osteoporosis: the World Health Organization (WHO) defined osteoporosis in 1996 as a disorder of systemic bone metabolism characterized by impaired microstructure of bone tissue, constant reduction of bone mineral composition and bone matrix in equal proportions, thinning of bone mass, reduced number of trabeculae, increased bone fragility and increased risk of fracture. The National Institutes of Health (NIH) redefined osteoporosis in 2001 as a disease of the skeletal system characterized by decreased bone strength and increased risk of fracture. The new definition emphasizes the concept of bone strength, which reflects two major aspects of bone, namely bone mineral density and bone mass. The disease can occur in different genders and at any age, but is more common in perimenopausal women (48-52 years), postmenopausal women (>52 years) and older men (>65 years). Osteoporosis is divided into two main categories: primary and secondary. Primary osteoporosis is subdivided into three types: postmenopausal osteoporosis (type I), senile osteoporosis (type II) and idiopathic osteoporosis (including adolescent type). Postmenopausal osteoporosis generally occurs within 5-10 years after menopause in women; senile osteoporosis generally refers to osteoporosis that occurs after the age of 70 in the elderly; secondary osteoporosis refers to osteoporosis caused by any disease or drug that affects bone metabolism; and idiopathic osteoporosis mainly occurs in adolescents, and the cause is unknown. Generally, what we call osteoporosis mostly refers to primary osteoporosis, that is, during the aging process, as age increases, bone tissue undergoes degenerative changes, calcium in bone is gradually lost, bone volume decreases, and the microstructure of bone tissue is destroyed, as a result, the brittleness of bone increases and fractures can easily occur. Osteoporosis is a degenerative disease and the risk of developing it increases with age. With the increase of human life expectancy and the aging of society, osteoporosis has become an important health problem for human beings. Currently, there are about 173 million people over 60 years old in China, about 90 million people suffer from osteoporosis and about 200 million people have low bone mass. Osteoporosis is more frightening than the two major killers of human beings – cancer and cardiovascular disease – because the latter occurs only in a small number of people, while the former will potentially affect the whole human race, potentially at all ages of one’s life, affecting human longevity, health and quality of life. Unfortunately, most people still have misconceptions about osteoporosis, believing that when people get older, hunching, bending or even fractures after a fall are irresistible normal physiological manifestations, which is the reason why osteoporosis is called the “hidden killer”. In fact, modern medicine considers osteoporosis to be a disease that can be completely avoided or controlled after occurrence.