Pituitary microadenomas are pituitary adenomas with a diameter of less than 1 cm. Most of the pituitary microadenomas do not have any effect on the patients and do not have obvious clinical symptoms, and they are found during physical examination or cranial MRI for other reasons. Asymptomatic pituitary microadenomas can be temporarily observed and only need regular review; some special microadenomas will cause endocrine hormone increase, such as prolactin, growth hormone, adrenocorticotropic hormone increase, the patient will have amenorrhea, breast overflow, infertility, giant sign, and full-moon face, buffalo back and other obvious clinical symptoms, which will need medication or surgical treatment.