After a child has a cold, doctors often remind parents to monitor their child’s hearing changes and pay attention to the prevention of otitis media. Some parents may ask: What does a cold have to do with the ear, and how can an upper respiratory tract infection visit the ear? Although medical research has not thoroughly identified the cause of otitis media in children, it has been found to be closely related to three major factors: eustachian tube dysfunction, infection and immune response. Of these, eustachian tube malfunction is the main cause. In children, adenoid hypertrophy is the most common cause of eustachian tube obstruction or eustachian tube malfunction. In addition, the disease is often secondary to an acute upper respiratory tract infection, most likely a mild or hypotoxic bacterial infection of the middle ear. Finally, because the middle ear is an independent immune defense system that is not yet developed in childhood, this is one of the major reasons why children are susceptible to this disease. Parents need to be aware of some of the “telltale signs” of otitis media in children so that early detection, diagnosis and treatment can be achieved. For example, children often show signs of dullness in listening or inattention. Older children may tell their parents that they have a stuffy or blocked feeling in their ears, a loss of hearing, or a ringing sound in their ears. It mostly occurs after a cold or unknowingly. Depending on the clinical symptoms of hearing loss, examination may reveal signs such as an invagination of the eardrum, pink or yellow oil, and hairlines. In rare cases, a diagnostic tympanocentesis under aseptic operation may be required to confirm the diagnosis. Acoustic impedance-conductance testing is the most commonly performed basic audiological diagnostic test and is an important reference for diagnosis and for determining the degree of disease recovery. The results of foreign evidence-based medical studies confirm that up to 96% of children have suffered from secretory otitis media and have a high recurrence rate, but parents need not be overly concerned. However, parents should not be overly concerned because most acute otitis media can heal on their own, and most of them can recover completely with reasonable treatment, and only a very small number of them need further surgical treatment. During the growth and development of children, hearing plays an important role in the comprehensive development of their cognitive ability and intelligence. Therefore, early diagnosis and reasonable treatment are necessary and urgent. Chronicity can be caused by not receiving timely and appropriate treatment during the acute phase, or by repeated attacks and delays.