Oxygen Saturation in Blood (Arterial)
This test measures how much oxygen is bound to hemoglobin in your blood, typically taken from an artery. It helps assess your body’s ability to deliver oxygen to tissues.
["Your blood’s oxygen levels can indicate lung function or blood flow issues."]
Key facts at a glance
- LOINC
- 34163-6
- Short code
- O2 Ct Bld-sCnc
- Synonyms
- O2 Ct Bld-sCnc
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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
What Does This Test Measure?
Oxygen saturation (SpO₂) reflects the percentage of hemoglobin molecules carrying oxygen in your arterial blood. It’s often measured using a finger probe during routine checks or via blood draws in clinical settings. This test is commonly used in emergencies or ongoing monitoring for conditions like heart disease, lung disorders, or anemia.
Why Might You Need This Test?
Doctors may order this test to evaluate breathing problems, detect low oxygen levels, or monitor chronic conditions like heart failure, COPD, or sleep apnea. It’s also used during surgeries or critical care to ensure proper oxygen delivery.
How Is the Test Performed?
For a blood draw, a healthcare provider will insert a small needle into an artery (usually in your wrist or arm) to collect a sample. The sample is analyzed immediately or sent to a lab for measurement. In some cases, a finger probe may measure oxygen saturation noninvasively.
What Are Common Uses?
This test is critical in diagnosing or managing conditions affecting oxygen transport, such as respiratory failure, severe anemia, or blood clots blocking arteries. It’s also used during anesthesia or in intensive care units to track oxygen levels in real time.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low oxygen saturation (below 90%) may signal serious issues like poor lung function, heart problems, or blood disorders. High saturation (above 100%) is rare but can occur in conditions like polycythemia (overproduction of red blood cells). Regular monitoring helps prevent complications and guides treatment decisions.
Short name
O₂ Saturation
Frequently asked questions
What does an abnormal result mean?
How often should I get this test?
Can lifestyle changes affect oxygen saturation?
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 16, 2026. · Read our editorial policy