The cervical mucus plug is a colorless or yellowish sticky liquid secreted by the cells of the cervical canal, which is usually thick and protects the body by separating the uterine cavity from the vagina and preventing retrograde bacterial infection. During ovulation, due to the action of estrogen, the mucus secreted by the cells of the cervical canal increases and becomes thinner in nature, which facilitates the smooth passage of sperm through the cervical canal to reach the uterine cavity and complete fertilization by combining with the egg. Circumstances and reasons affecting the amount of cervical mucus bolus 1. Low secretion of cervical mucus bolus: If the amount of cervical mucus during ovulation is <0.03ml, it can be diagnosed as low secretion. When the cervix is dysplastic, it is often accompanied by cervical glandular dysplasia, which affects the normal secretion function. 2. Excessive secretion of cervical mucus plugs: the amount of cervical mucus measured at one time during ovulation is ≥0.7 ml, or the amount of colorless and transparent cervical mucus is >0.4 ml for more than 4 consecutive days, which is considered as excessive mucus secretion and may be caused by chronic cervicitis, high estrogen level, polycystic ovary syndrome, etc. The cause needs to be clarified The cause of the problem should be identified and treated accordingly. Cervical mucus plugs have a certain protective effect on the cervix, but they can also be affected by a decrease in body resistance and an imbalance in acid-base balance, resulting in thinning and shedding.