Why Do I Get Altitude Sickness in Denver but Not in Airplanes?
Have you ever wondered why you experience altitude sickness while visiting high-altitude locations like Denver, but never while flying on airplanes? It may seem paradoxical, but the secret lies in how cabin pressure is regulated during air travel.
Understanding Altitude Sickness
Altitude sickness, also known as acute mountain sickness (AMS), occurs when your body is unable to adapt quickly enough to the decrease in oxygen levels at high altitudes. This can happen when you ascend to elevations above 8,000 feet (2,400 meters) in a short period (less than 24 hours).
The Pressurized Cabin Environment
Commercial airplanes are equipped with pressurized cabins that help maintain a comfortable and breathable atmosphere throughout the flight. These cabins are pressurized to simulate an altitude of around 6,000 to 8,000 feet (1,800 to 2,400 meters) above sea level. This pressure level is managed by the aircraft's air conditioning and pressurization systems.
How Cabin Pressure Affects Oxygen Levels
The air pressure in a typical plane cabin is equivalent to what you would experience at an altitude of around 8,000 feet. At this elevation, the air pressure is lower, which means there are fewer oxygen molecules per breath. However, the body can comfortably adapt to this situation because the breathing rate and oxygen need are minimal due to the stationary position of the passengers.
Why Doesn’t Airplane Pressure Cause Altitude Sickness?
During a flight, the respiratory system works efficiently because the body is at rest and not engaged in physical activities that would increase oxygen demand. If you were to climb a mountain in the wild, your lungs would need to work much harder to supply the body with enough oxygen. This increased effort strains the respiratory system and can lead to altitude sickness.
The Role of Passenger Type Aircraft
In passenger types of commercial aircraft, the cabin pressure is designed to prevent passengers from experiencing the adverse effects of high altitude. The International Standard Atmosphere (ISA) specifies that aircraft should not exceed an equivalent pressure altitude of 8,000 feet. Passengers are usually notified of this by the flight crew through safety briefings and post-boarding instructions.
Cabin Pressure in Smaller Aircraft
Smaller private aircraft, on the other hand, are often unpressurized and may be flown at altitudes much higher than 8,000 feet. When flying in these unpressurized aircraft, the cabin pressure is the same as the external pressure, which can lead to symptoms of altitude sickness, especially at higher-than-normal altitudes.
Conclusion
The key difference between experiencing altitude sickness in places like Denver and not on airplanes lies in the controlled atmosphere of the pressurized cabin. The body can adapt to the lower oxygen levels in a pressurized cabin but struggles when exposed to the lower oxygen levels at high altitudes beyond the adaptive range.
By understanding the role of pressurized cabins, we can explain why altitude sickness is a concern at higher elevations but not in the comfortable environment of a modern airplane.