As aircraft climbs, the higher pressure in the ear is equalized with outside air. However, in descent the eustachian tubes do not open automatically and pain is experienced in the ear. This condition is prominent when one is flying with sinus congestion or cold. In extreme cases it may result in injury to the ear.
A condition of blocked air. Air in the cavity of the middle ear expands and contracts in accordance with Boyle's law when changes in atmospheric pressure take place. During altitude changes, if the pressure differences with outside air are not equalized, the eardrum is distended and pain may be experienced in the affected ear. This condition is most prominent during descent, and a conscious effort has to be made to swallow or use the valsalva maneuver to clear the condition. To avoid injury to the middle ear, people should avoid flying when they have sinus congestion.