Cyclic ovulation of the ovaries causes cyclic shedding and bleeding of the endometrium, which is known as normal menstruation. The basal follicle takes about 10-14 days to develop and mature from the first day of menstruation. The peak of estrogen secreted by the mature follicle can cause a peak of luteinizing hormone (LH) in the body, which can induce ovulation. Before natural menopause, when the body is affected by internal and external factors that interfere with the ovulation process, ovulation may be delayed or may not occur. The first manifestation of anovulation is menstrual disorders. Delayed menstruation, menopause, irregular vaginal bleeding. Basal body temperature measurement is monophasic, vaginal discharge is not egg-white like change, and ovulation test is not strongly positive. Go to the hospital to perform ultrasound examination and find that the follicles do not grow, or luteinize, and the blood drawn for progesterone does not rise, etc. When ovulation does not occur, there is no sperm-egg union, resulting in female infertility. Without ovulation, there is no corpus luteum formation and insufficient progesterone, which makes the endometrium proliferate under single estrogen stimulation without progesterone transformation, and the endometrium is at risk of deterioration in the long run. The symptoms of anovulation need to be seen in the context of the cause. Mental, environmental and lifestyle changes should be adjusted in time or ovulation may resume naturally. In the case of polycystic ovary syndrome causing anovulation, it may be accompanied by hirsutism, acne, obesity, and gray-brown pigmentation in the skin folds, requiring long-term comprehensive management. Hyperprolactinemia may be associated with haloed nipples, milk production, etc., or may be associated with pituitary tumors, etc. Abnormal thyroid and adrenal function may be associated with altered temperament, irritability or apathy, neuropsychiatric disorders, etc. Central nervous system tumors such as craniopharyngioma cause anovulation and may be accompanied by corresponding signs of pressure. Oppositional ovarian syndrome leading to primary amenorrhea with ovarian anovulation. Hypogonadotropic hypogonadism, Turner syndrome, may be accompanied by abnormal development of secondary sex characteristics. In summary, ovulation is an important component of female reproductive function. When anovulation is detected, you should seek medical attention to find the cause, correct the unfavorable factors, and treat the original disease as soon as possible so that the ovaries can return to normal healthy ovulation.