When you fly at 33,000 feet, the atmosphere is under lower pressure than at sea level. If your nose is dry, or congested, your sinus openings may close up. Then the air inside your sinus is trapped, as though it were inside a closed bottle. At 33,000 feet, the atmosphere is about 10-pounds/ square inch. But when you descend, the atmospheric pressure at sea level is about 15-pounds/sq inch. There is now a five pound difference outside the sinus and inside the blocked sinus. The pain you get is just like having a five-pound weight on your eyeball!
Prevent this by keeping your body and your nose moist. Drink lots of tea, lemon and honey. Use a moisturizer gel to keep your nose moist. If you do feel a blockage, use a Benzedrex inhaler to open your sinuses. Once the inhaler opens the sinuses, then the pressures equalizes and you should be free of symptoms.
Treat barotraumas by opening the sinus openings and using an anti-inflammatory product to reduce the swelling of the delicate sinus tissues. In the average patient, there is no actual infection.