Most earaches are due to infections in the middle ear, the part of the ear between the eardrum and the inner ear. However, they may also be caused by accumulations of ear wax, a foreign body, or infections in the auditory canal, the tube leading from the outside to the eardrum. Occasionally, an earache occurs as referred pain from the mouth or jaw. For example, a severe toothache may also sometimes be felt as pain in the ear.
Infections in the middle ear, known medically as otitis media, are usually caused by streptococci or staphylococci bacteria. The bacteria enter the middle ear chamber through the Eustachian tube, a narrow canal that connects the middle ear with the back of the throat. By coughing, sneezing, or changing the air pressure in the middle ear (as in diving or flying), bacteria-laden particles from the throat may be carried into the middle ear. Shortly after the infection starts, the eardrum becomes inflamed and very painful. As pus accumulates inside the middle ear chamber, it presses upon the eardrum, creating a sense of fullness in the ear and sometimes producing a temporary loss of hearing.
The treatment of an earache depends upon the underlying cause. When ear wax or a foreign body is present, it must be removed; in most cases, the material is lodged so deeply in the auditory canal that it must be removed by a doctor.
Infections of the middle ear can be successfully treated by the administration of antibiotics, and the treatment should be started promptly to prevent complications, such as perforation of the eardrum or mastoiditis. A perforated eardrum may lead to chronic infections of the middle ear; it can be repaired through surgery. Mastoiditis is an infection in the part of the skull bone directly behind the ear. Most often, the infection can be effectively treated with antibiotics, but in some cases it is necessary to remove part of the bone (mastoidectomy).