Physiological cervical mucus is secreted by cervical glandular cells under the action of estrogen and progesterone, and is thin and transparent or white and thick, without odour. When the amount and character of cervical mucus changes, for example, when it becomes excessive, yellowish-purulent, smelly or mixed with blood, along with other unpleasant symptoms, it suggests the presence of organic pathology, mostly caused by cervical lesions.