Polycystic left ovary is usually a finding of a gynecologic ultrasound examination that indicates polycystic-like changes in the left ovary, which may only be a polycystic state and not a disease. This is because only if the ultrasound examination indicates polycystic ovarian changes and the patient has sporadic ovulation, abnormal menstruation and infertility, then it is a disease state, i.e. polycystic ovary syndrome. If the patient only has polycystic ovaries on the left side and normal ovaries on the right side, and there are no other abnormalities, the menstrual cycle and menstrual flow are normal, it usually does not affect conception. However, it is recommended to review regularly and pay attention to your menstrual condition as unilateral polycystic ovaries may become bilateral. If a patient has symptoms such as menstrual disorders, amenorrhea, obesity, acne and infertility along with ultrasound suggestive of polycystic left ovary, it is usually polycystic ovary syndrome. The specific cause of polycystic ovary syndrome is still unclear, but it is generally believed to be a combination of genetic and environmental factors that lead to abnormal regulation of the hypothalamic-pituitary-ovarian axis, which is an endocrine metabolic disease. Patients with polycystic ovary syndrome have a higher than normal chance of developing diabetes, hypertension, and endometrial cancer, and require regular checkups as well as treatment, including controlling dietary intake, increasing exercise, and, if necessary, medication and surgery.