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Oxygen Saturation (SaO₂) Measured During Resting Blood Draw with Pulse Oximetry

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

This test measures how well your blood is carrying oxygen while you’re at rest, using both a blood sample and a pulse oximeter device on your finger.

Quick summary

["Assesses oxygen levels and heart function during daily activity."]

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

Key facts at a glance

LOINC
59417-6
Short code
SaO2 Resting % BldA PulseOx
Synonyms
SaO2 Resting % BldA PulseOx
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
pulse-oximetry
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 Is Done

Your healthcare provider may order this test to check for conditions that affect how your body uses oxygen, such as lung diseases, heart problems, or anemia. It can also help monitor chronic conditions like heart failure or COPD.

How the Test Works

A small blood sample is drawn from your arm while you’re resting. Simultaneously, a pulse oximeter measures oxygen levels in your finger blood flow. The test combines these results to provide an accurate snapshot of your oxygen saturation.

What to Expect Before the Test

No special preparation is needed. You may be asked to sit quietly for a few minutes before the blood draw to ensure accurate results. Wear comfortable clothing that allows easy access to your arm and finger.

What to Expect During the Test

You’ll lie down or sit comfortably while a healthcare professional draws a small amount of blood from your arm. At the same time, a small sensor is placed on your finger to measure oxygen levels. The process takes about 5–10 minutes total.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low oxygen saturation (below typical reference ranges) may indicate lung disorders, poor circulation, or other health issues. High saturation (above typical ranges) could suggest conditions like polycythemia (overproduction of red blood cells). Regular monitoring helps manage chronic conditions and adjust treatments as needed.

Short name

Resting Oxygen Saturation

Frequently asked questions

How long does it take to get results from this test?
Results are typically available within 1–2 business days, depending on your lab’s processing time. Your healthcare provider will discuss them with you during your follow-up visit.
Can I eat or drink before this test?
No special diet is required. However, if you’re taking certain medications (like blood thinners), always check with your provider first to avoid any potential delays or complications.
Is there any pain or discomfort during the test?
There may be a slight pinch during the blood draw, but the finger sensor is painless. Most people describe it as a mild sensation similar to a quick pinch. You can ask for numbing cream if you’re sensitive to pain.
  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