Lower oxygen levels contribute to the fatigue you're feeling. Because plane cabins are pressurized to simulate a 6,000-8,000 feet elevation, your blood absorbs less oxygen at those altitudes. This can cause dizziness, sleepiness, and a lack of mental sharpness.

Yes, it is completely normal to experience "Travel Fatigue" after a flight, even if you haven't crossed multiple time zones. This exhaustion is caused by several factors beyond just jet lag: the lower oxygen levels in a pressurized cabin (equivalent to being at 6,000–8,000 feet), the extremely low humidity (often under 10%) which causes dehydration, and the physical stress of "micro-vibrations" from the engines. Additionally, the cognitive load of navigating airports and the "white noise" of the cabin can drain your mental energy. In 2026, doctors also point to the lack of movement causing poor circulation as a major contributor to post-flight lethargy. While Jet Lag is specifically about your internal clock being out of sync, travel fatigue is a physical response to the environment of the aircraft itself, and it typically fades after 24 hours of rest and proper hydration.