The reason for this is that all of the above-mentioned diseases can easily cause the Eustachian tube to become incompetent, and when the airplane takes off or descends too fast, the external air pressure increases rapidly and negative pressure forms in the tympanic chamber, causing the tympanic membrane to sink and damaging the middle ear. This can lead to otitis media. Therefore, if you are suffering from any of the above mentioned diseases and are in a serious condition, please do not take a flight for the time being. If you have special circumstances that require you to fly, you can prepare for the flight by using nasal drops or furosemide 20 minutes before takeoff to constrict the blood vessels and reduce the pressure on the eustachian tube. This will greatly reduce the chances of otitis media.