Glucose, Serum or Plasma (Quantitative)
This test measures the amount of glucose (sugar) in your blood drawn from either your vein or a fingerstick.
["Your blood sugar level helps monitor diabetes or other conditions affecting blood sugar."]
Key facts at a glance
- LOINC
- 6756-1
- Short code
- Glucose 4.5h p 75 g Glc PO SerPl-mCnc
- Synonyms
- Glucose 4.5h p 75 g Glc PO 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 order glucose tests to check for diabetes, monitor blood sugar levels in people with diabetes, detect prediabetes, or evaluate symptoms like excessive thirst, frequent urination, or unexplained weight changes.
What to Expect Before the Test
No special preparation is needed unless instructed by your healthcare provider. You may be asked to fast (not eat) for 8–12 hours before a fasting blood draw, but non-fasting tests can also be done for general monitoring.
What Happens During the Test?
A healthcare professional will clean your arm with an antiseptic and insert a small needle to draw blood. You may feel a slight pinch, but the procedure is quick. If tested via fingerstick, a small prick is made on your fingertip.
What Happens After the Test?
The blood sample is sent to a lab for analysis. Results are typically available within a few hours to a day, depending on the lab. You’ll receive your results from your doctor.
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, poor blood sugar control, or other metabolic issues. Low levels can signal hypoglycemia (low blood sugar), especially in people with diabetes or other conditions. Frequent monitoring helps manage these conditions effectively.
Short name
Glucose Level
Frequently asked questions
How long does it take to get my glucose test results?
Can I eat or drink before this test?
What does a ‘fasting’ glucose test mean?
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