I. What is osteoporosis Osteoporosis is a systemic bone disease characterized by low bone mass, destruction of bone microstructure, resulting in increased bone fragility and susceptibility to fracture (WHO). In 2001, the National Institutes of Health (NIH) proposed that osteoporosis is a disease of the skeletal system characterized by decreased bone strength and increased risk of fracture, and that bone strength reflects two major aspects of bone, namely bone mineral density and bone mass. 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). The osteoporosis induced by some factors such as other diseases or drugs is called secondary osteoporosis. The most common clinical conditions are postmenopausal osteoporosis and senile osteoporosis. It is necessary to pay attention to distinguish two concepts, osteoporosis is not equal to osteopenia, osteopenia is a disease process without any symptoms, when there is bone pain, fragility fracture is called osteoporosis. Second, how to diagnose osteoporosis World Health Organization (WHO) recommends the use of dual-energy X-ray equipment (DXA) measurement of lumbar Ll-4, femoral neck and total hip bone density, with reference to the Caucasian young women peak bone mass reduction of 2,5 standard deviation (-2,5SD), as a criterion for the diagnosis of osteoporosis. (a) Prevalence of osteoporosis Osteoporosis is a common and frequent disease. About 30% of women aged 50 to 60 in China suffer from postmenopausal osteoporosis, the prevalence of women over 60 is about 30% to 50%, and the prevalence of osteoporosis in elderly men is about 20% to 30%. (B) risk factors for the development of osteoporosis 1, inherent factors ethnicity (the risk of osteoporosis is higher in Caucasians and yellow than in Blacks), thinness, old age, premature menopause in women (before 40 years of age), and family history of senile fractures. 2. Non-inherent factors (1) lifestyle factors Smoking, excessive alcohol consumption, high intake of coffee and tea, inappropriate dieting to lose weight, too light or high protein diet, lack of physical activity (braking). (2) Nutritional factors Nutritional imbalance in the diet, excessive or insufficient protein intake, high sodium diet, low body weight, calcium and/or vitamin D deficiency (low light or low intake). (3) Disease factors Hypogonadism, chronic gastrointestinal disorders, chronic liver and kidney insufficiency, diabetes, hyperthyroidism, ovarian, uterine, large gastric, small intestine resection, etc. (4) Drug factors Taking glucocorticoids, antiepileptic drugs, thyroid hormones and methotrexate and other drugs affecting bone metabolism. The incidence of osteoporosis in all patients treated with glucocorticoids for more than 6 months is about 50%. What is the danger of osteoporosis The biggest danger of osteoporosis to human body is fracture, and the risk of fracture gradually increases with age or other factors. The most common are hip fractures, distal radius fractures and spinal compression fractures. Distal radius fractures often cause severe pain confined at the wrist joint and significant deformity of the wrist joint, resulting in severe impairment of joint function. Hip fractures often present clinically with severe disease, often with delayed healing or non-healing, and often with a poor prognosis due to osteoporosis. Compression fractures of the spinal vertebrae present with sudden onset of severe back pain, and the fracture mass sometimes compresses the nerve roots in the corresponding plane and causes limb paralysis and dysfunction, causing inconvenience to the patient’s life and family. In addition, osteoporosis can cause hunchback, shortening of the body and respiratory diseases. In short, osteoporosis will bring a lot of harm to the patients, which will bring some pain to the patients themselves and also bring financial burden to the families.