During the healing process of cervical erosion, the new squamous epithelium covers the mouth of the cervical glandular ducts or extends into the glandular ducts, blocking the mouth of the glandular ducts; the connective tissue around the glandular ducts grows or scar tissue forms to compress the glandular ducts, narrowing or even blocking them, and the drainage of glandular secretions is obstructed and trapped to form cysts.