Ear barotrauma, or "clogged ear," is a common condition that can occur when the air pressure in the middle ear differs from the surrounding air pressure. While it's common among air travelers, ear barotrauma also afflicts scuba divers, mountain climbers and people driving to high altitude locations. In most cases, it can be cleared up by yawning or swallowing. These actions equalize the air pressure by opening the ear's eustachian tube, allowing the outside air to flow through the ear.
When yawning or swallowing doesn't do the trick, ear barotrauma only gets worse, resulting in uncomfortable pressure in the ears or head. This can happen as the result of any pre-existing condition that leaves a traveler with a congested nose, which impedes airflow through the eustachian tube. So if you're suffering from allergies, a cold or an upper respiratory infection, you can help prevent ear barotrauma by taking an antihistamine, an oral decongestant, nasal spray or a prescribed steroid before boarding your flight. In extreme cases, ear barotrauma can be caused by a birth defect of the eustachian tube, which can be remedied only with surgery.
While ear barotrauma is common, it's not responsible for every case of in-flight head discomfort. Every year there are a number of people who suffer from flight-related headaches that have little or nothing to do with inner ear air pressure. Although researchers have yet to pinpoint the exact cause of this phenomenon, many point to a variety of factors that may contribute to the problem, like poor air quality, engine noise and overall stress from traveling. To prevent these symptoms from occurring, doctors recommend practicing relaxation techniques or cutting out stress-inducing factors by wearing a sleeping mask or earplugs. Or you can take the old-fashioned route by downing a headache tablet prior to flying.
Another suspected cause of in-flight head discomfort is the barometric pressure headache. When the barometric pressure rises or falls, the oxygen level in the air also changes. Some medical experts believe the blood vessels in a person's head expand and contract to compensate for this change, which is the same thing that occurs when someone suffers from a migraine or a vascular headache. To relieve the pain caused by a barometric pressure headache, doctors recommend applying an ice pack to the back of the neck and another on the area where the pain seems to radiate from.