In Reply to: fainting on plane posted by balihopeful on Monday, 4. June 2012 at 12:47 Bali Time:
"During a flight, the barometric pressure of an airplane cabin is lower than most places on Earth. The majority of commercial aircraft are designed to be pressurized to the equivalent of an elevation of 6,000 to 8,000 feet. This decreased pressure environment diminishes our bodies' ability to absorb oxygen and can produce light-headedness or other altitude sickness symptoms in some people.
While generally not an issue on planes, the lack of oxygen can result in a condition called hypoxia. Hypoxia is the technical term for a lack of oxygen to the organs in the body, including the brain.
One of the minor symptoms of hypoxia is mild intoxication, similar to what is experienced after consumption of alcohol. Granted, physiological changes associated with fluctuations in barometric pressure and alcohol intoxication are complex.
Blood alcohol content (BAC) and the way the body processes alcohol under such environmental conditions probably stays the same as on land. Meaning, some people may seem more drunk in the air than on the ground after consuming the same amount of alcohol, because of the lower oxygen levels in their blood.
Another thought to consider is that the air on planes is very dry (it helps preserve the interior of the plane). Add in the diuretic impact of alcohol and a person can become dehydrated much faster than on the ground. Some health professionals and travel experts recommend avoiding alcohol before or during flying for these very reasons. Others will advocate for alternating at least eight ounces of water between alcoholic beverages (both on the ground and in the air).
While the impact of alcohol while flying can appear stronger, it's not really double strength at altitude".
Sorry to hear of your scary experience, maybe the above might help to explain.
Flying home yesterday, I also felt a wee bit faint, but I blame it on consuming way too much alcohol and not drinking enough water to stay hydrated. I passed out, fell asleep snoring louder than the crying kid a few rows back and awoke 21 minutes prior to landing.