Glucose, Serum or Plasma (Mass Concentration)
This test measures the amount of glucose (sugar) in your blood, typically drawn from a vein or collected in a serum or plasma sample.
["Glucose levels help monitor blood sugar and identify conditions like diabetes or metabolic issues."]
Key facts at a glance
- LOINC
- 40858-3
- Short code
- Glucose BS BldC-mCnc
- Synonyms
- Glucose BS BldC-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 order glucose tests to check for high or low blood sugar, diagnose diabetes, evaluate symptoms like excessive thirst or fatigue, or monitor treatment for conditions like diabetes or kidney disease. It may also be used during pregnancy to screen for gestational diabetes or before certain surgeries.
What to Expect Before the Test
You may need to fast for 8–12 hours before the test, especially if it’s a fasting glucose check. If you’re pregnant, breastfeeding, or have a medical condition, let your provider know. Avoid smoking or caffeine before the draw to get the most accurate results.
During the Test
A healthcare professional will insert a small needle into a vein in your arm to draw blood. You may feel a slight pinch, but the process is quick. If you’re nervous, ask about numbing cream or other comfort options.
After the Test
You can resume normal activities immediately. Apply gentle pressure to the site to stop bleeding, and check for any unusual swelling or redness. Report any severe pain or signs of infection (like fever) to your provider.
Reference range
Fasting: 70-100 mg/dLN/A
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.
High glucose levels may indicate diabetes, prediabetes, or other metabolic disorders, while very low levels could signal hypoglycemia (low blood sugar), adrenal insufficiency, or liver/kidney problems. Repeated testing helps track trends and adjust treatments like medication or diet.
Short name
Glucose Level
Frequently asked questions
How Often Should I Get This Test?
What If My Results Are Abnormal?
Does Diet or Exercise Affect This Test?
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