Osteoporosis is a systemic bone disease characterized by a decrease in bone mass and deterioration of bone microstructure, resulting in increased brittleness of bone and susceptibility to fracture. Osteoporosis can cause: (1) pain. Low back pain is common, which is relieved when lying on the back or sitting, and increased when standing upright or standing or sitting for a long time, and is light during the day and increased at night and in the morning when waking up, and increased when bending, muscle movement, coughing and straining. (2) Shortening of body length and hunchback. Most of the time, the pain is followed by compression of the vertebral body in osteoporosis, which shortens the length of the body and causes hunchback. (3) Fracture. This is the most common and serious complication of osteoporosis, which not only increases the patient’s pain and aggravates the financial responsibility, but also severely limits the patient’s activities and even shortens life expectancy. Primary osteoporosis is closely related to calcium deficiency in the body, but some patients with osteoporosis not only do not have calcium deficiency, but also develop high blood calcium. This type of osteoporosis is secondary and is mostly associated with hyperparathyroidism. Hyperthyroidism refers to a series of clinical changes caused by excessive secretion of parathyroid hormone. It is classified as primary or secondary. Primary hyperparathyroidism is caused by adenoma, hyperplasia and adenocarcinoma, while secondary hyperparathyroidism is associated with renal insufficiency and dialysis. Due to excessive secretion of parathyroid hormone, calcium is mobilized from bone to blood circulation, causing excessive blood calcium, while renal tubular reabsorption of inorganic phosphorus is reduced, urinary phosphorus excretion is increased, and blood phosphorus is reduced. Due to the autonomy of the tumor, high blood calcium cannot inhibit parathyroid glands, so blood calcium continues to increase. If renal function is intact, urinary calcium excretion increases and blood calcium decreases slightly, but the effect of continuously increasing parathyroid hormone causes extensive bone resorption and decalcification, and metabolites such as bone matrix decomposition, mucin and hydroxyproline increase from urinary excretion, forming urinary calculi or renal calcium salt deposition (nephrocalcinosis). nephrocalcinosis) and secondary infections, renal function is often severely impaired. In the later stages of renal insufficiency, phosphate is not excreted sufficiently and the blood phosphorus concentration may increase, while blood calcium may decrease, which may stimulate increased thyroid secretion (secondary hyperfunction in extra-neoplastic tissues). Although osteoclast mobilization is the main cause of the disease, osteoblast activity also increases compensatorily, so that serum alkaline phosphatase increases every time. Therefore, don’t forget to check the parathyroid glands in case of osteoporosis, bone pain, multiple fractures and other pathologies.