What is a blood gas test?

By Lana Barhum

A blood gas test is also called an arterial blood gas test or a blood gas analysis. It measures oxygen and carbon dioxide levels in the blood. The test can also show blood pH levels and lung function.

Doctors often use blood gas tests in emergency situations to help diagnose the cause of breathing difficulty.

In this article, learn more about the purpose of a blood gas test and how to interpret the results.

Purpose

A blood gas test can help to diagnose lung problems.

Anyone who is struggling to breathe or who has a lung-related health issue will undergo a blood gas test. The results can help a doctor to identify the cause of symptoms.

A blood gas test can show how well the lungs, heart, and kidneys are working.

More specifically, results of the test can help a doctor to:

• diagnose lung and breathing problems
• check whether treatments for lung conditions are working
• determine whether a person has a ruptured blood vessel, metabolic disease, or chemical poisoning

Doctors also use the test to check the acid-base balances in people who:

• have kidney problems
• have diabetes
• are recovering from drug overdoses