Polycystic ovarian change refers to the presence of multiple small follicles in the ovaries. Examination of the ovaries under ultrasound with ≥12 small follicles per section, that is, the ovaries have multiple follicles developing at the same time, is called polycystic ovarian change, which is only a symptom, not a disease. Polycystic ovary syndrome is an endocrine disease, and polycystic ovarian changes is one of the diagnostic criteria of polycystic ovary syndrome. There are three indicators to classify polycystic ovary syndrome by international standards: 1) sparse ovulation or anovulation; 2) ovarian polycystic changes; 3) clinical manifestations of hyperandrogenism or hyperandrogenemia, two of which can be considered polycystic ovary syndrome. Therefore, a single ovarian polycystic change is only a symptom, and other indicators can be observed to exclude polycystic ovary syndrome.