What do the results of a blood oxygen level test mean?

Blood test reports, including blood oxygen level test reports, usually provide the following information:

The name of the blood test or what was measured in your blood.

The number or measurement of your blood test result.

The normal measurement range for that test.

Information that indicates if your result is normal or abnormal or high or low.

If your blood oxygen level blood test results are not normal, 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).

A blood oxygen level test can't diagnose specific conditions. If your results are not normal, your healthcare provider will have you undergo more tests to confirm or rule out a diagnosis.

Laboratories may have different reference ranges for the aspects of your blood that are measured in a blood oxygen level test. 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.

For most people, a normal pulse oximeter reading for your oxygen saturation level is between 95% and 100%. If you have a lung disease such as COPD or pneumonia, your normal oxygen saturation level may be lower. Your healthcare provider will let you know what levels are acceptable. Your oxygen saturation levels may also be lower if you live in an area with high elevation.

It’s important to note that pulse oximeters are not always accurate. Your actual blood saturation level may be 2% to 4% higher or lower than what the oximeter reads. For a more accurate result, your provider may check your blood oxygen levels with a blood test.

A lower-than-normal blood oxygen level is called hypoxemia. Since oxygen is essential to all of your body’s functions, hypoxemia is often concerning. The lower the oxygen level, the greater likelihood for complications in body tissue and organs.

A variety of conditions and circumstances can interfere with your body’s ability to deliver normal levels of oxygen to your blood. Some of the most common causes of low blood oxygen levels (hypoxemia) include:

If you have a low blood oxygen level, your healthcare provider will likely have you undergo further testing to determine what is causing your low oxygen levels. A blood oxygen level test alone cannot determine the cause.

The results for a blood sample oxygen level test are usually available right away (within minutes).

A pulse oximeter reveals your oxygen saturation level within seconds.

If you’re using an oximeter at home and your oxygen saturation level is 92% or lower, call your healthcare provider. If it’s at 88% or lower, get to the nearest emergency room as soon as possible.

If you have a chronic lung condition, such as COPD or asthma, you’ll likely need to see your healthcare provider regularly to make sure your treatment is working. If you develop concerning symptoms related to your lung condition, call your provider as soon as possible.