Glucose (Serum or Plasma) Concentration
This test measures the amount of glucose (sugar) in your blood, typically taken from serum or plasma. It helps assess how well your body is using sugar for energy and managing blood sugar levels.
["A glucose test helps monitor blood sugar control, especially important for diabetes management."]
Key facts at a glance
- LOINC
- 25674-3
- Short code
- Glucose 45M p chal SerPl-sCnc
- Synonyms
- Glucose 45M p chal SerPl-sCnc
- Category
- glucose
- Sample
- serum
- Container
- Red-top tube (SST)
- 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
- 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 This Test Is Done
Doctors order glucose tests to check for conditions like diabetes, high or low blood sugar, or to monitor treatment effectiveness. It may also be used during pregnancy, before surgeries, or to diagnose metabolic disorders.
What to Expect Before the Test
You may be asked to fast (not eat) for 8–12 hours before the test, especially if it’s a fasting glucose check. If fasting isn’t required, you can eat normally. Bring any medications you’re taking to your appointment.
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 pinch, but it usually doesn’t cause significant discomfort. The blood sample is sent to a lab for analysis.
What the Results Mean
Results are compared to general reference ranges, but your specific range may vary based on your health, age, and test type (e.g., fasting vs. random). High or low readings may signal diabetes, hypoglycemia, or other health concerns.
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.
◆Associated findings1
Short name
Glucose Level
Frequently asked questions
What causes abnormal glucose levels?
How can I lower my glucose levels if they’re too high?
It depends on the test type. Some glucose tests require fasting (e.g., fasting plasma glucose), while others (like random glucose) can be done anytime. Always confirm with your healthcare provider before the appointment.
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