Glucose, Plasma Concentration
This test measures the amount of glucose (sugar) present in your blood plasma. It helps assess how well your body is managing blood sugar levels.
["This test helps monitor blood sugar control, often used in diabetes management or after fasting."]
Key facts at a glance
- LOINC
- 39479-1
- Short code
- Glucose Pcar-sCnc
- Synonyms
- Glucose Pcar-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 Is This Test Done?
Doctors may order this test to check for diabetes, monitor blood sugar levels in people with diabetes, evaluate symptoms like excessive thirst or fatigue, or assess metabolic health. It can also be used before surgeries or during pregnancy to ensure stable blood sugar.
What to Expect Before the Test
For a plasma glucose test, you may need to fast for 8–12 hours before the test. If fasting isn’t required, you’ll typically have blood drawn from a vein in your arm. The test is quick and usually painless, but you might feel a slight pinch. If you’re pregnant or have a history of bleeding disorders, let your doctor know.
What Happens During the Test?
A healthcare provider will insert a small needle into your arm to draw blood into a tube. The blood is then sent to a lab for analysis. The test itself takes only a few minutes, but the blood draw may take slightly longer. You’ll usually be able to return to your normal activities immediately afterward.
What Do Results Mean?
Results are compared to general reference ranges, but your doctor will interpret them based on your medical history, symptoms, and other tests. High or low glucose levels can signal diabetes, prediabetes, or other health conditions. Your doctor will discuss any findings with you.
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.
Clinical Significance
Short name
Plasma Glucose Level
Frequently asked questions
What Are Common Questions About This Test?
Can I eat or drink anything before the test? If fasting is required, avoid food and liquids (except water) for the specified period. If fasting isn’t required, you can eat and drink normally, but avoid sugary drinks or snacks that might affect results.
How often will I need this test? Frequency depends on your health condition. People without diabetes may need this test occasionally for general health checks, while those with diabetes may need it monthly or more often to monitor their treatment.
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