Bacteria or viruses commonly cause ear infections in the middle ear. These infections frequently occur due to another illness, such as a cold, flu, or allergy, which causes swelling and congestion in the nasal passages, throat, and eustachian tubes.
The eustachian tubes are a pair of narrow lines that connect each middle ear to the back of the throat, behind the nasal passages. These tubes open and close to regulate air pressure, refresh air, and drain normal secretions from the ear. If the eustachian tubes become swollen, they may block and cause fluid to build up in the middle ear, leading to infection. The eustachian lines are narrower and more horizontal in children, making them more prone to blockages.
Adenoids are two small pads of tissue located high in the back of the nose that are believed to play a role in immune system activity. If the adenoids become swollen and block the opening of the eustachian tubes, it can lead to middle ear infections. This is more common in children, who have larger adenoids than adults.
Other middle ear conditions related to ear infections or similar problems include otitis media with effusion, chronic otitis media with flow, and chronic suppurative otitis media. These conditions can result in swelling, fluid buildup, and even a hole in the eardrum.