What causes a Middle Ear Infection?
The causes can begin with the blockage of the Eustachian tube during a cold, allergy, or upper respiratory infection, and the presence of bacteria or viruses lead to a build-up of pus and mucus behind the eardrum. This infection is called acute otitis media. The build-up of pressurized pus in the middle ear causes pain, swelling, and redness. Since the eardrum cannot vibrate properly, hearing problems may occur.