Normal mature follicles are about 18-22mm in size. During the follicular phase under the influence of the body’s endocrine environment, estrogen and progesterone and follicle stimulating hormone, the follicle begins to develop, and when the diameter of the follicle is >6mm, it is called the dominant follicle. When the dominant follicle continues to grow and develop and reaches 18-20mm, it suggests that the follicle is close to maturity and then enters the ovulation phase. Under the combined influence of luteinizing hormone, follicle stimulating hormone and estrogen and progesterone, when the follicle reaches a diameter of 18 to 22 mm, it suggests that the follicle has matured. Under the influence of hormone levels, the follicle surface ruptures and the egg is discharged, completing the ovulation process. In general, when the follicle is >20mm, it will usually rupture and discharge the egg in 24 to 48 hours. If there are follicle development abnormalities, it is recommended to go to a regular hospital in time to improve the relevant examination, under the guidance of a professional doctor to clarify the cause, and early treatment, to avoid delaying the condition.