Hyperparathyroidism can be divided into four types: primary, secondary, tertiary and pseudo. Primary hyperparathyroidism is caused by excessive synthesis and secretion of parathyroid hormone (PTH) due to parathyroid gland lesions (tumors or hyperplasia), which leads to hypercalcemia and hypophosphatemia through its effects on bones and kidneys. Clinical features include recurrent kidney stones, peptic ulcers, mental changes and extensive bone resorption. In recent years, many patients have been discovered in time due to routine serum calcium measurements. These patients often have no obvious symptoms except hypercalcemia and increased serum PTH. Secondary hyperparathyroidism is caused by hypocalcemia due to various reasons, which stimulates the parathyroid glands to proliferate and hypertrophy, and secrete excessive PTH. It is common in diseases such as renal insufficiency, osteomalacia, intestinal malabsorption, vitamin D deficiency and hydroxylation disorders. On the basis of secondary hyperparathyroidism, due to persistent stimulation of the gland, some hyperplastic tissues are transformed into adenomas, which autonomously secrete excessive PTH, which is called tertiary hyperparathyroidism, which is rare in clinical practice. Pseudohyperparathyroidism refers to the secretion of PTH-like polypeptide substances by certain malignant tumors (such as lung, liver, kidney and ovarian malignant tumors), which causes hypercalcemia, called tumor-associated hypercalcemia.