
Most ear infections form in the middle ear. The eustachian tube carries fluid from the middle ear to the throat. Sometimes during a cold, the eustachian tube becomes swollen and fluid is trapped in the middle ear. Bacteria or viruses can grow in this fluid and form an ear infection.
| By | Healthwise Staff |
| Primary Medical Reviewer | Susan C. Kim, MD - Pediatrics |
| Specialist Medical Reviewer | Charles M. Myer, III, MD - Otolaryngology |
| Last Revised | September 10, 2012 |