Pituitary tumors do not occur in everyone. Pituitary tumors are a pathological state, as pituitary gland cells or mesenchymal cells mutate abnormally to form tumor cells, which in turn proliferate and become tumors. Therefore, pituitary tumors do not occur in everyone. The population of pituitary tumors is still a minority after all, and most people are normal. The occurrence of pituitary tumors is related to the mutation or variation of oncogenes and oncogenes in the body, as well as environmental factors, and not everyone will develop pituitary tumors in their lifetime. Pituitary tumors can be classified in a variety of ways, such as by size or by the abnormal hormone levels involved.