Otitis media is an inflammation of the middle ear - the space between the eardrum and the inner ear. This space is usually filled with air, but during a cold or other infection it may become filled with mucus or fluid, which in turn may become infected with bacteria.
There are a number of different types of middle ear infection, including acute otitis media (a short-term condition that comes on suddenly) and chronic otitis media (a long-term infection or repeated attacks of infection). Chronic otitis media may also be associated with a build up of thickened fluid in the ear, when it is known as secretory otitis media or 'glue ear'.
In this section, you'll find information on the causes and symptoms of middle ear infections, along with a guide to their diagnosis and treatment.