Otitis media results from disruption of eustachian tube patency. In the suppurative form, bacterial infection is usually the cause; other causes include respiratory tract infection, allergic reaction, nasotracheal intubation, or positional changes that allow flora to reflux through the eustachian tube and colonize the middle ear. Chronic suppurative otitis media results from inadequate treatment for acute otitis episodes, infection by resistant bacteria or, rarely, tuberculosis. Obstruction of the eustachian tube causes a buildup of negative pressure and eustachian tube dysfunction. Barotrauma from rapid aircraft descent in a person with an upper respiratory tract infection or during rapid underwater ascent in scuba diving may produce barotitis media. Chronic secretory otitis media may result from mechanical obstruction (adenoidal tissue overgrowth or tumors), edema (allergic rhinitis or chronic sinus infection), or inadequate treatment for acute suppurative otitis media.

Complications include spontaneous rupture of the tympanic membrane, mastoiditis, meningitis, cholesteatomas (cystlike masses in the middle ear), septicemia, abscesses, vertigo, lymphadenopathy, sigmoid sinus or jugular vein thrombosis, suppurative labyrinthitis, facial paralysis, otitis externa, tympanosclerosis, and permanent hearing loss.

Many patients are asymptomatic. Clinical features of acute suppurative otitis media include severe, deep, throbbing pain; signs of upper respiratory tract infection; mild to very high fever; hearing loss; tinnitus; dizziness; nausea; and vomiting. Bulging of the tympanic membrane with erythema may occur; purulent drainage may be present from tympanic membrane rupture. Pain may stop suddenly when the membrane ruptures. Acute secretory otitis media produces a severe conductive hearing loss, a sensation of fullness in the ear, and popping, crackling, or clicking sounds on swallowing or with jaw movement. Accumulation of fluid may cause the patient to hear an echo when speaking and to have a vague feeling of top-heaviness. In chronic otitis media, thickening and scarring of the tympanic membrane occur with decreased or absent tympanic membrane mobility.