Oxygen level tests

Oxygen level tests check the level of oxygen in your blood and can be helpful to diagnose or monitor lung conditions. This information covers pulse oximetry, blood gas tests and fitness-to-fly (hypoxic challenge) tests.

Oxygen level tests

A woman sitting down, with a pulse oximeter on her finger.

Pulse oximetry

Pulse oximetry is a test to measure the level of oxygen in your blood. Find out how to prepare for a pulse oximetry test, how it works and what the results mean.
A doctor and patient sat down in a doctor's office. The doctor is showing the patient information on the screen of a tablet.

Blood gas test

A blood gas test is used to accurately measure the levels of oxygen and carbon dioxide in your blood. Find out what happens during a blood gas test and what the results mean.
A person on an aeroplane, putting their suitcase in the overhead luggage storage.

Fitness-to-fly (hypoxic challenge) test

A fitness-to-fly test is used to find out if you need extra oxygen when flying. This information includes what happens during a fit-to-fly test and what the results mean.
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