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Glucose in Plasma (24-hour profile)

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

This test measures your blood sugar levels over a 24-hour period using plasma samples. It helps assess how your body manages glucose throughout the day, especially useful for diagnosing or monitoring conditions like diabetes or insulin resistance.

Quick summary

["Understanding how your blood sugar fluctuates helps doctors diagnose and manage diabetes or other metabolic conditions."]

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

Key facts at a glance

LOINC
12628-4
Short code
Glucose DiafP-mCnc
Synonyms
Glucose DiafP-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 Is Done

Your doctor may order this test if they suspect you have diabetes, prediabetes, or another condition affecting blood sugar control. It’s also used to evaluate how well medications or lifestyle changes are working to manage glucose levels over time.

How the Test Works

Plasma samples are collected at specific times (often before meals and after meals) to measure glucose concentration. The results are analyzed to create a profile of your glucose levels throughout the day.

Sample Collection and Preparation

You’ll need to fast before some samples are taken, while others may be collected at different times. Follow your healthcare provider’s instructions carefully to ensure accurate results.

What to Expect Before the Test

Avoid eating or drinking anything except water for a set period before some sample collections. Wear comfortable clothing and bring any prescribed medications with you.

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

24-Hour Plasma Glucose Profile

Frequently asked questions

How often will I need to provide samples?
Samples are typically collected at multiple times over 24 hours, often including before meals and after meals. Your doctor will specify the exact schedule.
Will fasting be required for all samples?
No, some samples may be collected at non-fasting times, depending on your doctor’s instructions. Always confirm with your healthcare provider.
What happens if my glucose levels are outside the expected range?
If results are abnormal, your doctor may recommend further testing, lifestyle changes, or adjustments to medications to better manage your blood sugar.
  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