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Glucose in Blood (Mass Concentration)

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

This test measures the amount of glucose (sugar) in your blood, typically drawn from a vein or fingerstick.

Quick summary

["Glucose levels help monitor blood sugar and identify risks for diabetes or other metabolic conditions."]

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

Key facts at a glance

LOINC
41651-1
Short code
Glucose BldA-mCnc
Synonyms
Glucose BldA-mCnc
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, monitor blood sugar levels in people with diabetes, detect low blood sugar (hypoglycemia), or assess how your body processes glucose during certain medical conditions.

How Is the Test Performed?

A healthcare provider will draw blood from a vein in your arm or use a small needle to prick your finger to collect a drop of blood. The sample is sent to a lab for analysis.

What Do Results Mean?

Results are compared to general reference ranges, but individual needs may vary. High or low readings may signal underlying health concerns that require further evaluation.

Common Reasons for Abnormal Results

Elevated glucose levels may indicate diabetes, poor insulin function, or stress-related spikes. Low levels can cause fatigue, dizziness, or confusion and may require immediate medical attention.

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

Blood Glucose

Frequently asked questions

What causes blood glucose levels to be too high?
High blood glucose can result from diet high in sugar or refined carbs, lack of physical activity, certain medications, or underlying conditions like diabetes. Stress, illness, or hormonal changes can also play a role.
What should I do if my glucose test is low?
If your glucose is low (hypoglycemia), eat a quick source of sugar like fruit juice, candy, or glucose tablets. Seek immediate medical help if symptoms like severe shakiness, confusion, or loss of consciousness occur.
Do I need to fast before this test?
For routine glucose tests, fasting is not required unless specified by your doctor. If fasting is needed (e.g., for fasting glucose), follow your provider’s instructions to ensure accurate results.
  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