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Oxygen saturation in arterial blood (measured via pulse oximetry or blood gas analysis)

Published: August 9, 2026Updated: August 16, 2026

This test measures how well your blood carries oxygen to your body’s tissues. It’s often checked during routine health assessments or when you have symptoms like shortness of breath.

Quick summary

["Helps assess lung function and oxygen delivery efficiency in everyday health checks or emergencies."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
60796-0
Short code
Target O2 end exp VFr/PPres Away adap
Synonyms
Target O2 end exp VFr/PPres Away adap
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

Why It’s Done

Your doctor may order this test if you have symptoms like dizziness, fatigue, rapid breathing, or if you have conditions like heart disease, lung problems, or anemia. It’s also used during surgeries, anesthesia, or in critical care settings to monitor oxygen levels in real time.

What to Expect Before the Test

You’ll likely have a small sensor placed on your finger to measure your pulse and blood oxygen levels. No special preparation is needed, but avoid smoking or caffeine 30 minutes before the test if instructed.

What the Results Mean

Normal results typically indicate healthy oxygen levels (around 95% or higher). Lower values may signal issues like poor lung function, heart problems, or blood disorders. Your doctor will discuss results in the context of your overall health.

Common Conditions Affecting Results

Conditions like chronic obstructive pulmonary disease (COPD), heart failure, or severe anemia can lower oxygen saturation. Smoking, high altitude, or certain medications may also impact readings.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Arterial Oxygen Saturation (SpO₂)

Frequently asked questions

How often do I need this test?
This test is often done as needed—either for routine monitoring, symptoms, or specific medical reasons. Your doctor will determine how frequently it’s required based on your health status and treatment plan.
Can I eat or drink before this test?
No special diet or fasting is required for this test. However, if your doctor has specific instructions (e.g., for a blood draw), follow those instead.
What if my oxygen saturation is low?
If your results are below normal, your doctor may recommend further tests (like a blood gas analysis) or treatments such as oxygen therapy, lifestyle changes, or managing underlying conditions like heart or lung disease.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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