Glucose (Serum or Plasma) by Enzymatic Method
This test measures the amount of glucose (sugar) in your blood, typically drawn from a vein in your arm.
["Your blood sugar levels help manage energy and prevent complications like diabetes."]
Key facts at a glance
- LOINC
- 12643-3
- Short code
- Glucose 8h p chal SerPl-mCnc
- Synonyms
- Glucose 8h p chal SerPl-mCnc
- 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 Is This Test Done?
Doctors may order this test to check for diabetes, monitor blood sugar control, assess symptoms like extreme thirst or fatigue, or evaluate conditions affecting metabolism or circulation.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast (not eat) for 8–12 hours before the test if it’s part of a fasting glucose study.
How the Test Is Performed
A healthcare provider will insert a small needle into a vein in your arm to draw blood. You may feel a slight pinch, but it usually doesn’t cause long-lasting discomfort.
What the Results Mean
Results help determine if your blood sugar is too high or too low, guiding treatment decisions. Abnormal levels may indicate diabetes, prediabetes, or other metabolic issues.
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 or low glucose levels can signal serious health risks, including nerve damage, heart disease, or kidney problems. Regular monitoring helps prevent long-term complications and ensures proper management of conditions like diabetes.
Short name
Glucose Level
Frequently asked questions
What causes blood sugar to rise?
Frequency depends on your health status. People with diabetes may need tests monthly or more often, while others may only need occasional checks. Follow your doctor’s recommendations.
High levels may require lifestyle changes (diet, exercise) or medication. Low levels (hypoglycemia) can cause dizziness or confusion—seek help if symptoms occur.
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