Arterial Hemoglobin Oxygen Saturation (SaO₂) via Calculated Arterial Blood Gas Analysis
This test measures how well your blood is carrying oxygen from your lungs to your body’s tissues. It’s often part of an arterial blood gas (ABG) panel to assess lung function and oxygen levels.
["Helps diagnose and monitor conditions affecting oxygen delivery in your blood."]
Key facts at a glance
- LOINC
- 55781-9
- Short code
- Hct VFr Mar Calc
- Synonyms
- Hct VFr Mar Calc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 36
- Ref high
- 50
- Critical range
- 18 N/A – 60 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- calculated
- CPT
- 85014
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Does This Test Measure?
SaO₂ measures the percentage of oxygen bound to hemoglobin in your arterial blood. Normal oxygen saturation typically ranges between 95% and 100%, but this can vary based on health status and medical conditions. Low SaO₂ may indicate lung problems, heart issues, or other health concerns.
Why Might You Need This Test?
Your doctor may order this test if you have symptoms like shortness of breath, fatigue, or rapid heartbeat. It’s also used before surgeries, during critical illnesses, or to monitor chronic conditions like COPD or heart disease.
How Is the Test Performed?
A small sample of blood is taken from an artery (usually in your wrist) using a needle. The blood is analyzed immediately to measure oxygen saturation. This test is quick and usually done in a hospital or clinic setting.
What Are Common Results?
Results are reported as a percentage (e.g., 92%). A lower-than-normal SaO₂ may suggest poor lung function or breathing difficulties, while a higher-than-normal reading could indicate polycythemia (too many red blood cells).
Reference range
Adult males: 38-50%; Females: 36-44%N/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
SaO₂ (Arterial Oxygen Saturation)
Frequently asked questions
What causes low arterial oxygen saturation?
What if my SaO₂ is normal but I still feel short of breath?
Can I prepare for this test?
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