Rhinitis causing otitis media seems to tell people that the nose and the ear are connected. Then why doesn’t the snot come out of the ear when the ear is placed in the lowest position? The reason is that the nasal cavity is connected to the pharyngeal cavity, which in turn has the eustachian tube leading to the middle ear tympanic chamber, so the nose and the ear are connected. Since the eustachian tube is very short, wide and flat in young children, infection in the nasopharynx can easily spread along the mucous membrane of the eustachian tube to the tympanic chamber, thus causing otitis media. The pharyngeal opening of the eustachian tube is not at the same level as the lateral wall of the nasal cavity, and the mucous membrane of the eustachian tube is crepuscular, which prevents the pharyngeal liquid from entering the tympanic chamber, so it is difficult for clear nasal snot to flow into the eustachian tube. If the doctor puts the ear drops into the outer ear canal of the child and then asks the child to swallow them and feels bitter in the mouth after a few minutes, it means that the eardrum of the child has been broken and the liquid has entered the pharynx from the middle ear through the eustachian tube. When you find that your child has frequent runny nose, it means that there is likely inflammation in the nasopharynx, and if it is accompanied by headache, it may be due to otitis media. If you find pus flowing from the external ear canal, it indicates that the eardrum has collapsed. As the pressure of the pus on the tympanic chamber is reduced, the headache can be reduced accordingly at this time. It is important to note that when pus is found in a child’s ear, do not use insoluble dry powder to sprinkle it into the ear, as this may block the ear canal and prevent the pus from flowing out, causing the inflammation to develop towards the mastoid process, resulting in meningitis and systemic infection.