Q: What can cause pituitary hyperplasia and how can it be treated? Is this a common occurrence? A: Pituitary hyperplasia is pathologically speaking a disorganization of normal pituitary cells, change in shape, increase in hypertrophy of certain cells, increase in intercellular tissue and so on. Its biological characteristics are between normal cells and tumor cells. Pituitary hyperplasia is divided into physiological (normal) and pathological (pathological). There are many causes of pituitary hyperplasia. Pathological hyperplasia refers to a factor that induces abnormal hypertrophy and abnormal secretion of one or even more pituitary cells. For example, PRL cell hyperplasia appears as hyperprolactinemia, which manifests as lactation, menstrual disorders, etc.; growth hormone cell hyperplasia manifests as gigantism, enlarged hands and feet, etc. These tend to persist for many years or are permanent, with some turning into tumors or returning to normal. Hypothyroidism or hypoadrenocorticism feedback causes hyperplasia of pituitary thyroid hormone secreting cells and adrenocorticotropic hormone cells; there are also drug-induced pituitary hyperplasia, such as sedative drugs for the treatment of psychiatric disorders that induce hyperplasia of pituitary cells. Most of these conditions are not suitable for surgery or radiation therapy. The treatment of different causes will have good results.