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Glucose in Serum (24-Hour Profile)

Published: August 9, 2026Updated: August 17, 2026

This test measures your blood sugar levels over a 24-hour period to assess how your body manages glucose, often used to evaluate diabetes control or metabolic health.

Quick summary

["This test helps track how your body responds to glucose throughout the day, useful for managing conditions like diabetes."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
11047-8
Short code
GPI RBC-cCnc
Synonyms
GPI RBC-cCnc
Category
glucose
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
4.2
Ref high
5.9
Critical range
2 N/A – 7 N/A
Fasting
true
Population
adult
Sex
all
Age range
18–65 years
CPT
85041
SNOMED
900000000000003001
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

A 24-hour glucose profile is typically ordered to check for patterns in blood sugar levels that may not be apparent from single measurements. It helps doctors identify if you’re experiencing highs or lows at specific times, which can affect treatment plans for diabetes or other metabolic disorders.

What to Expect Before the Test

You’ll need to fast overnight before the test, and blood samples will be collected at regular intervals over 24 hours. Your doctor or nurse will provide detailed instructions on diet and activity restrictions to ensure accurate results.

How the Test Works

Blood is drawn from a vein (usually in your arm) at set times—often including before meals and after eating—to measure glucose concentration. The samples are analyzed in a lab using standard methods to detect glucose levels.

What the Results Mean

Results show glucose trends, helping doctors determine if your body produces enough insulin, responds properly to it, or if other metabolic issues (like kidney or liver problems) may be affecting glucose levels.

Reference range

Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A

Specimen: whole-blood

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Serum Glucose Monitoring

Frequently asked questions

How often should I expect this test?
This test is usually done once per year or more frequently if you have diabetes or other metabolic conditions. Your doctor will determine the timing based on your health needs.
What should I do if I miss a blood draw?
If you miss a scheduled blood draw, contact your healthcare provider immediately to reschedule. Missing samples can affect the accuracy of your 24-hour glucose profile results.
Can I eat or drink anything before the test?
No, you must fast (no food or liquids except water) for 12–14 hours before the test starts. Follow your doctor’s specific instructions to ensure valid results.
  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 17, 2026. · Read our editorial policy