This animation describes normal ovulation and then what occurs during PCOS, caused by an imbalance in reproductive hormones. Having PCOS also predisposes a woman to other health risks such as type II diabetes (non insulin dependent, controlled by weight), heart disease, high blood pressure, cholesterol problems and endometrial cancer.
Abnormally high levels of lutenising (LH) hormone result in many follicles in the ovary, that remain in an immature state. Without a dominant maturing follicle ovulation fails (anovulation). The immature follicles do not degrade properly and remain as fluid filled cysts in the ovary. High insulin levels are common in PCOS and when combined with high LH, results in elevated testosterone. High testosterone results in anovulation and is also responsible for the other characteristics of PCOS such as acne and excess hair growth.
Watch the video on YouTube (link opens in new window).