Eustachian tubes are small passageways that connect behind the nose to the middle ears. When you sneeze, swallow or yawn, the Eustachian tubes open to allow air to flow in and out. However, sometimes, Eustachian tubes can become blocked which is called Eustachian tube dysfunction. When this happens, sounds become muffled and your ear may feel full.
The most common causes of Eustachian tube dysfunction is caused by cold (flu) or sinusitis.
Most of the time, the Eustachian tube dysfunction will resolved without any treatment.