Oxygen Saturation in Whole Blood (from Arterial Blood Gas)
This test measures how much oxygen is bound to hemoglobin in your blood, specifically from an arterial blood sample. It helps assess your body’s ability to deliver oxygen to tissues.
["Check your oxygen levels to identify potential breathing or circulation issues."]
Key facts at a glance
- LOINC
- 51732-6
- Short code
- SaO2 % BldC from pO2
- Synonyms
- SaO2 % BldC from pO2
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 80
- Ref high
- 100
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- calculated-from-oxygen-partial-pressure
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Oxygen saturation is critical for diagnosing conditions like low oxygen levels (hypoxia), respiratory disorders, or circulation problems. It’s often used alongside blood gas tests to evaluate lung function and overall health.
What to Expect During the Test
A healthcare provider will take a small sample of blood from an artery (usually in your arm) using a needle. You may feel a slight pinch, but the procedure is quick. The blood is analyzed immediately to measure oxygen saturation levels.
Common Conditions Monitored
This test is commonly used to monitor conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, or during surgeries or medical procedures where oxygen levels may change.
Preparation and Care
No special preparation is needed, but avoid smoking or heavy exercise before the test. If you’re on oxygen therapy, let your provider know so they can adjust the test accordingly.
Reference range
NCBI: PaO2 80-100 mmHgN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Arterial Blood Oxygen Saturation (SaO₂)
Frequently asked questions
Oxygen saturation results help determine if your body is getting enough oxygen. Low levels (below 90%) may indicate serious issues requiring medical attention, while normal levels (typically 95% or higher) suggest healthy oxygen delivery.
Can I fast before this test? No fasting is required for this test, as it involves a blood sample rather than a urine or fasting blood glucose test.
Is there any risk or discomfort? The procedure involves a small needle insertion, which may cause mild discomfort or bruising. Rarely, there could be minor bleeding or infection risk, but complications are uncommon.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy