Glucose, 20-minute postprandial concentration in serum
This test measures your blood sugar level 20 minutes after eating a meal, helping assess how your body responds to food.
["Helps identify how well your body manages blood sugar after eating."]
Key facts at a glance
- LOINC
- 40194-3
- Short code
- Glucose 20M pre chal SerPl-sCnc
- Synonyms
- Glucose 20M pre 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
Your healthcare provider may order this test if you have diabetes or prediabetes, or if you’re at risk for blood sugar issues. It can also help monitor how well your current diabetes treatment is working or check for problems like hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar) after meals.
What to Expect Before the Test
You’ll eat a standard meal (often a carbohydrate-rich one) and then fast for about 20 minutes before the blood is drawn. The test is usually done in a lab setting, and you may feel a small pinch when blood is collected.
What the Results Mean
Results are compared to your baseline or other relevant measurements to see how your body handles glucose after eating. Abnormal results may signal how your pancreas or other systems are managing blood sugar.
Common Causes of Abnormal Results
High results might indicate poor glucose tolerance, while very low results could suggest reactive hypoglycemia or an underlying condition affecting blood sugar regulation.
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.
This test helps diagnose or monitor conditions like diabetes, prediabetes, or metabolic disorders by evaluating how quickly blood sugar rises and falls after eating. It’s also useful for evaluating how medications or treatments impact glucose control.
Short name
Glucose (20 min post-meal)
Frequently asked questions
What does a high or low result mean for my health?
Do I need to prepare differently if I’m pregnant or have certain medications?
How often should I get 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