Medical Concerns with flying.


Hypoxia is an insufficient supply of oxygen to the cells. Hypoxia is incredibly dangerous as it causes the brain and other vital organs to become impaired. Additionally, the symptoms of hypoxia vary based on the person, and can be hard to detect. I personally have felt ill and lightheaded as a result of hypoxia, but the next time I experience hypoxia might have different symptoms.

There are 4 types of hypoxia noted in the PHAK:

  • Hypoxic hypoxia: Too little oxygen as a whole for the body. It’s a concern as you increase in altitude, there’s less air overall, which can result in too little oxygen.
  • Hypemic Hypoxia: There’s sufficient oxygen in the air, but not enough in the blood. Most commonly caused by CO poisoning. Can also be caused by recent (within the past several weeks) blood donation and exacerbated by flying at altitude.
  • Stagnant Hypoxia: The blood can take up the oxygen, but it is unable to be transported to the organs. Can be caused by heart problems, excessive acceleration, a constricted blood vessel, or cold temperatures.
  • Histotoxic Hypoxia: The oxygen is able to be transported via the blood to the organs, but the organs are unable to use it. Usually caused by alcohol or drugs. “drinking one ounce of alcohol can equate to an additional 2,000 feet of physiological altitude” - PHAK.


Excessive rate and depth of respiration. Causes an excessive amount of CO2 to be removed from the body. Similar symptoms to hypoxia. Breathing into a paper bag or talking aloud helps recovery.

Last updated: 2021-05-29 09:20:33 -0700