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Glucose in Serum/Plasma (24-Hour Profile)

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

This test measures your blood glucose levels over a 24-hour period using a sample of your serum or plasma. It helps track how your body manages glucose throughout the day, which is useful for managing conditions like diabetes.

Quick summary

["Understanding your body’s glucose control over time can help prevent complications and tailor your treatment plan."]

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

Key facts at a glance

LOINC
19105-6
Short code
Glucose 3h p Glc SerPl-Imp
Synonyms
Glucose 3h p Glc SerPl-Imp
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 recommend this test if you have diabetes or are at risk of developing it. It helps assess how well your body responds to food, medication, or other factors affecting blood sugar levels during the day.

How the Test Works

A small sample of your blood is collected at multiple times over 24 hours. Glucose levels are measured using an enzymatic method, which detects the presence of glucose in your blood serum or plasma.

Sample Collection Process

You’ll need to follow specific instructions for fasting or timing meals around blood draws. Typically, samples are taken at intervals (e.g., every few hours) to capture glucose fluctuations accurately.

What to Expect Before the Test

You may be asked to keep a food diary or track your activities to ensure accurate results. Avoid alcohol or certain medications that could affect glucose levels before testing begins.

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 Glucose Monitoring

Frequently asked questions

How often should I have this test?
Your doctor will determine the frequency based on your health needs, but it’s often done once or twice a year for stable patients or more frequently if you’re managing diabetes or other conditions affecting glucose.
What does a normal result mean?
A normal result doesn’t mean your glucose levels are perfectly stable—it shows your body’s overall ability to manage glucose over time. Your doctor will interpret results in the context of your medical history and other test results.
Can lifestyle changes affect this test?
Yes! Diet, exercise, stress, and sleep can influence glucose levels. Keeping a consistent routine and tracking your habits can help your doctor make better recommendations.
  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