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Serum or plasma mass concentration of glucose (24-hour profile)

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

This test measures the amount of glucose (sugar) in your blood over a 24-hour period, using a blood sample.

Quick summary

["A 24-hour glucose profile helps assess how your body handles sugar over time."]

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

Key facts at a glance

LOINC
55504-5
Short code
GH 2h p Gc SerPl-mCnc
Synonyms
GH 2h p Gc SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
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 healthcare provider may order this test to diagnose or monitor conditions like diabetes, prediabetes, or unexplained blood sugar fluctuations. It can also help evaluate how well your body responds to insulin or other treatments.

How the Test Works

Blood is collected at multiple time points (typically every 3–4 hours) to create a detailed picture of your glucose levels throughout the day. The sample is analyzed for glucose concentration using a mass concentration method.

Sample Collection

You’ll need to fast for 8–12 hours before the first blood draw. Blood samples are taken at scheduled intervals, often including before and after meals, to track glucose changes.

Preparation

Follow fasting instructions carefully. Avoid caffeine, alcohol, or strenuous activity before testing. Notify your provider of any medications or supplements you take, as they may affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

How long does a 24-hour glucose test take?
The test itself takes about 1–2 hours per blood draw, but the entire 24-hour process spans multiple days. You’ll need to schedule visits at consistent intervals to ensure accurate results.
What should I eat or drink during the test?
You’ll follow a strict fasting period before the first draw and avoid eating or drinking anything (except water) during the test unless instructed otherwise. Stick to your usual meals and snacks after the final blood draw.
Can I exercise during the 24-hour glucose test?
Moderate exercise is usually allowed, but avoid intense workouts or activities that could significantly alter your blood sugar levels. Check with your provider before starting any physical 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