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Glucose in Serum (24-Hour Profile)

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

This test measures your blood glucose levels over a 24-hour period using serum samples, helping assess how your body manages sugar intake and insulin function.

Quick summary

["This test helps identify patterns in blood sugar levels that may indicate diabetes, insulin resistance, or other metabolic conditions."]

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

Key facts at a glance

LOINC
11869-5
Short code
GA est formula Eq'n
Synonyms
GA est formula Eq'n
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 doctor may order this test if you have symptoms like frequent thirst, unexplained weight changes, fatigue, or if you have risk factors for blood sugar issues, such as a family history of diabetes or obesity. It may also be used to monitor treatment effectiveness in people with known diabetes or metabolic disorders.

How the Test Works

Blood samples are collected at multiple time points (typically every 4–6 hours) over 24 hours. Glucose levels are measured in the serum portion of your blood using a sensitive analytical method, often an enzymatic technique, to detect sugar concentrations.

Sample Collection Process

You’ll need to fast overnight before the test begins. During the 24-hour period, you’ll have small blood draws at scheduled times while eating and drinking normally. Avoid strenuous activity or medications that could affect glucose levels.

What to Expect Before the Test

You’ll receive detailed instructions on fasting, timing of meals, and avoiding certain foods or drinks that could skew results. Bring your medications list to confirm none interfere with the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Serum Glucose Profile

Frequently asked questions

What does a 24-hour glucose test tell me about my health?
It shows how your blood sugar fluctuates throughout the day, which can reveal whether you have diabetes, insulin resistance, or other metabolic issues that single tests might miss.
How often should I get this test?
Your doctor will determine frequency based on your medical history, symptoms, and treatment plan. Typically, it’s done once or twice a year for people with diabetes or metabolic concerns.
Can I eat or drink anything before the test?
No—you must fast overnight before the test starts. Follow your doctor’s specific instructions for fluids and meals during the 24-hour period.
  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