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2-Hour Postprandial Glucose (Serum/Plasma)

Published: August 9, 2026Updated: August 16, 2026

This test measures your blood glucose level two hours after eating a meal. It helps assess how well your body manages blood sugar levels over time.

Quick summary

["Helps check if your body handles glucose properly after meals."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
102020-5
Short code
Glucose 2h p Gc SerPl-mCnc
Synonyms
Glucose 2h p Gc 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 This Test Matters

Your doctor may order this test if they suspect you have diabetes, prediabetes, or other conditions affecting blood sugar control. It’s part of evaluating how your body responds to food and helps prevent complications like nerve damage or heart disease.

What to Expect Before the Test

You’ll typically fast for 8–12 hours before the test, but the 2-hour glucose measurement itself is done after eating. Bring written instructions from your healthcare provider to confirm fasting rules. Bring any medications you’re taking, as they may affect results.

How the Test Works

A healthcare professional will draw blood from a vein in your arm. The sample is sent to a lab where glucose levels are measured using an enzymatic method. Results are compared to reference ranges to determine if your blood sugar is within normal limits or if further action is needed.

What the Results Mean

Results may indicate normal glucose levels, prediabetes (elevated but not diabetic), or diabetes (consistently high). Your doctor will interpret results in the context of your overall health and may recommend lifestyle changes, medications, or follow-up tests.

Reference range

Fasting: 70-100 mg/dLN/A

Specimen: serum

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 after eating

Frequently asked questions

Will I need to fast before this test?
Yes, you’ll need to fast for 8–12 hours before the initial blood draw, but the 2-hour glucose measurement is taken after eating. Follow your doctor’s specific instructions to ensure accurate results.
Can I take my usual medications before the test?
Some medications (like insulin or diabetes drugs) may affect results. Ask your doctor whether to adjust your dose or skip certain medications on the day of the test.
How long will I have to wait for my results?
Results may be available within days to a few weeks, depending on your lab. Your doctor will contact you with the final interpretation and next steps.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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