Arterial Blood Gas (ABG)

If your arterial blood gas test results are abnormal, it may mean you:

Aren't taking in enough oxygen.

Aren't getting rid of enough carbon dioxide.

Have an imbalance in your blood pH (it's too acidic or basic).

An arterial blood gas test can help diagnose certain conditions. If your results are abnormal, your healthcare provider may order additional tests, such as other blood tests. and/or imaging tests, to confirm or rule out a diagnosis.

What are normal values for an arterial blood gas test?

Normal value ranges can vary slightly from lab to lab. When you get your blood test results back, there will be information that indicates what that lab's normal ranges are for each measurement. If you have any questions about your results, be sure to ask your healthcare provider.

In general, normal values at sea level include:

pH: 7.35-7.45.

Partial pressure of oxygen (PaO2): 75 to 100 millimeters of mercury (mmHg).

Partial pressure of carbon dioxide (PaCO2): 35 to 45 mmHg.

Bicarbonate (HCO3): 22 to 26 milliequivalents per liter (mEq/L).

Oxygen saturation (02Sat or SaO2): 95 to 100%.

At altitudes of 3,000 feet (900 meters) and higher, the normal oxygen level is lower.