Why are oxygen masks given to patients? Can't they take in the atmospheric oxygen? Also, why do they die if the oxygen mask stops providing oxygen?

  • $\begingroup$ these patients are being given oxygen in higher concentrations than the atmosphere contains. usually due to an in ability to uptake oxygen effectively. $\endgroup$
    – John
    Nov 27, 2017 at 18:04

1 Answer 1


Oxygen masks can provide up to near 100% oxygen, whereas the atmosphere contains only ~20%. Typically, oxygen is provided in cases where patients' blood oxygen saturation is low or is likely to be low.

Giving a patient supplemental oxygen helps them to achieve oxygen saturation even if their breathing or circulation is impaired, and allows slightly more oxygen to be dissolved in the blood, which can be helpful in cases of blood loss or other traumatic insults.

I'm not sure of any cases where patients simply die immediately if their oxygen mask fails, outside of movies/TV; it's more of an issue of trying to provide the best outcome possible in a difficult situation.

There are also some negative side effects of oxygen supplementation. Overall, Wikipedia has a reasonable overview of these, as well as the indications for oxygen supplementation.

  • $\begingroup$ 70 children died in India because the oxygen supply was cut. Why did that happen? $\endgroup$ Aug 13, 2017 at 17:30
  • 2
    $\begingroup$ I might have misread an immediacy in your statement (like they die immediately when oxygen is removed), based on the common media trope, not realizing you were motivated by a recent news event. The children most likely died because they had illnesses that prevented them from getting enough oxygen through normal breathing; supplemental oxygen could improve their blood oxygenation enough to keep them alive. When the supplemental oxygen was withdrawn, they would asphyxiate. $\endgroup$
    – Bryan Krause
    Aug 13, 2017 at 17:36

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