The concept is a disorder of systemic bone metabolism characterized by damage to the microstructure of bone tissue, a constant decrease in bone mineral composition and bone matrix in equal proportions, thinning of bone mass, a decrease in the number of trabeculae, increased bone fragility and an increased risk of fracture. In medicine, osteoporosis was first proposed by Pornmer in 1885, but it was not until the International Symposium on Osteoporosis held in Denmark in 1990 that a clear definition of osteoporosis was given and recognized worldwide: primary osteoporosis is a systemic disease characterized by a decrease in bone mass and degeneration of bone microstructure, resulting in increased bone fragility and susceptibility to fracture. Bone disease. (1) Primary osteoporosis: such as senile osteoporosis, postmenopausal osteoporosis, etc. (2) Secondary osteoporosis: such as hyperthyroidism osteoporosis, diabetic osteoporosis, etc. (3) Idiopathic osteoporosis of unknown cause: such as hereditary osteoporosis, etc. (1) Systemic osteoporosis: such as senile osteoporosis, hyperthyroidism osteoporosis, etc. (2) Limited osteoporosis: such as rheumatoid arthritis osteoporosis, local osteoporosis caused by the fixation of limb plaster, etc. Etiology and pathology (1) The reduction of sex hormone secretion in middle and old people is one of the important causes of osteoporosis. It is a recognized fact that estrogen level decreases after menopause, resulting in increased bone resorption. (2) With age, the secretion of calcium-regulating hormones becomes dysregulated, resulting in disorders of bone metabolism. (3) The elderly have a lack of protein, calcium, phosphorus, vitamins and trace elements due to the loss of teeth and lower digestive function, poor bone nano, and less intake of goodness. (4) With the growth of age, the reduction of outdoor exercise is also an important reason why the elderly are prone to osteoporosis. (5) Recent studies in molecular biology have shown that osteoporosis is closely related to vitamin D receptor (VDR) gene variants. Clinical symptoms (1) Pain. The most common symptom of primary osteoporosis is low back pain, which accounts for 70%-80% of the patients with pain. Pain spreads along the spine to both sides, decreases when supine or sitting, increases when posterior extension or prolonged standing or sitting, is light during the day, increases at night and when waking up in the morning, and increases when bending, muscle movement, coughing, and bowel straining. Bone pain generally occurs when 12% or more of bone mass is lost. In old age osteoporosis, the vertebral trabeculae atrophy and decrease in number, the vertebral body compresses and deforms, the spine flexes forward, the lumbar rash muscle doubles its contraction in order to correct the forward flexion of the spine, the muscle fatigue or even spasm, producing pain. A recent compression fracture of the thoracolumbar spine can also produce acute pain, with strong pressure pain and percussion pain in the spinal spinous process at the corresponding site, which can generally be gradually reduced after 2-3 weeks, and some patients can present with chronic low back pain. If the corresponding spinal nerve is compressed, radiating pain in the extremities, sensory-motor disorders in both lower extremities, intercostal neuralgia, retrosternal pain similar to angina pectoris, or epigastric pain similar to acute abdomen may occur. If compression of the spinal cord and cauda equina also affects bladder and rectal function. (2) Shortening of body length and hunchback. Most of them appear after the pain. The front part of the vertebrae of the spine is composed of almost all cancellous bones, and this part is the pillar of the body with a large weight, especially the 11th and 12th thoracic vertebrae and the 3rd lumbar vertebrae, which have a greater load and are easily compressed and deformed, causing the spine to tilt forward and the dorsal curvature to increase, resulting in a hunchback. Each person has 24 vertebrae, the height of each vertebra is about 2cm, when the elderly osteoporosis vertebrae compression, each vertebrae shortened about 2mm, the average length of 3-6cm shortened.(3) fracture. This is the most common and serious complication of degenerative osteoporosis. (4) Decreased respiratory function. Compression fractures of the thoracic and lumbar vertebrae, backward curvature of the spine, and thoracic deformity can significantly reduce lung capacity and maximum air exchange, and patients can often suffer from chest tightness, shortness of breath, and dyspnea.