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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 to help assess how your body manages sugar (glucose) throughout the day and night.

Quick summary

["Understanding your glucose control helps identify patterns that may affect diabetes management or other metabolic conditions."]

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

Key facts at a glance

LOINC
47761-2
Short code
GH 1h p Glc PO SerPl-aCnc
Synonyms
GH 1h p Glc PO SerPl-aCnc
Category
glucose
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
true
Population
adult
Sex
all
Age range
18–65 years
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 you have diabetes, prediabetes, or symptoms like frequent urination, extreme thirst, or unexplained weight changes. It helps track how well your body regulates blood sugar, especially if you take medications or insulin.

How the Test Works

Blood samples are collected at scheduled intervals (often every few hours) to measure glucose concentration. Results are analyzed to show trends in your glucose levels over the full day.

What to Expect Before the Test

No special preparation is needed, but follow your doctor’s instructions about diet, activity, or medications on the day of testing. Avoid skipping meals or exercising heavily before collection times.

What the Results Mean

The test provides a detailed profile of your glucose levels, helping identify patterns like spikes, drops, or consistency. Abnormal patterns may indicate poor control of diabetes or other metabolic issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Glucose levels outside normal ranges can signal diabetes, insulin resistance, or other conditions like hypoglycemia. Repeated testing helps doctors tailor treatment plans to your specific needs.

Short name

24-Hour Glucose Profile

Frequently asked questions

How often should I expect this test?
This test is typically done once or twice a year for stable diabetes management. Your doctor may adjust frequency based on your condition, treatment, or symptoms.
What if my glucose levels are consistently high or low?
Consistently high levels may mean your diabetes isn’t well-controlled, while low levels (hypoglycemia) could indicate overmedication or other issues. Your doctor will review results with you to adjust care plans.
Can I eat or drink before blood is drawn for this test?
Yes, but avoid skipping meals or fasting unless instructed by your doctor. Follow their guidance to ensure accurate results, as glucose levels fluctuate with food and activity.
  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