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Glucose in Whole Blood (Concentration)

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

This test measures the amount of glucose (sugar) in your blood, which helps assess how well your body is using energy and managing blood sugar levels.

Quick summary

["Glucose levels can indicate risk for diabetes, hypoglycemia, or other metabolic conditions."]

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

Key facts at a glance

LOINC
39481-7
Short code
Glucose BldA-sCnc
Synonyms
Glucose BldA-sCnc
Category
glucose
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
70
Ref high
100
Critical range
50 N/A – 400 N/A
Fasting
true
Population
adult
Sex
all
Age range
18–65 years
CPT
82947
SNOMED
260395008
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 Is This Test Done?

Doctors may order this test to check for diabetes or prediabetes, monitor blood sugar control in people with diabetes, diagnose hypoglycemia (low blood sugar), or evaluate conditions affecting metabolism, such as liver or kidney disease.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a fasting glucose panel. Bring any medications you’re taking and let your provider know about allergies or conditions like diabetes.

How the Test Is Performed

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a slight prick, but the procedure is quick and usually doesn’t cause discomfort. The blood sample is sent to a lab for analysis.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Your doctor will compare these numbers to your individual reference range and clinical context to determine if further action is needed.

Reference range

Fasting: 70-100 mg/dLN/A

Specimen: whole-blood

Fasting for 8-12 hours required. Water is permitted. Avoid chewing gum and smoking before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Glucose Level (Blood)

Frequently asked questions

What causes high glucose levels?
High glucose levels can result from diabetes, poor diet, stress, illness, or certain medications. If you suspect this test is abnormal, discuss your symptoms and medical history with your doctor.
How often should I get this test?
Frequency depends on your health status. People without diabetes may get this test occasionally for screening or routine checkups, while those with diabetes may need it monthly or more often to monitor treatment.
Can I eat or drink before the test?
If fasting is required, avoid food and liquids (except water) for 8–12 hours before the test. If fasting isn’t needed, eat a normal meal and drink as usual, but tell your provider about any medications you take.
  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