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

Quick summary

["Understanding your glucose levels at different times helps diagnose conditions like diabetes or insulin resistance."]

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

Key facts at a glance

LOINC
1630-3
Short code
GH 2h p 1 g/kg Glc PO SerPl-mCnc
Synonyms
GH 2h p 1 g/kg Glc PO SerPl-mCnc
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 recommend this test if you have symptoms of diabetes (such as frequent urination, extreme thirst, or unexplained weight changes), if you have a family history of diabetes, or if you’re at risk due to other health conditions like obesity or high blood pressure. It can also help monitor how well your current treatment plan is working.

What to Expect Before the Test

You’ll typically fast overnight before this test. Follow your doctor’s instructions carefully about when to eat or drink. Blood is drawn from a vein in your arm at different times over 24 hours to collect samples.

What the Results Mean

The results show your glucose levels at various points during the day, helping identify patterns. For example, high levels in the morning or evening might indicate insulin resistance or other metabolic issues.

Common Conditions Linked to Glucose Testing

Abnormal results may signal diabetes (type 1 or type 2), prediabetes, or conditions affecting how your body uses glucose, such as pancreatitis or certain hormonal disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

24-Hour Serum Glucose Profile

Frequently asked questions

How often should I get this test if I have diabetes?
If you have diabetes, your doctor may recommend this test less frequently than a standard glucose check (e.g., every few months) to monitor trends over time, but individual needs vary. Regular follow-ups with your healthcare provider are key to adjusting your treatment plan.
Can I eat or drink anything before the blood draws?
No, you’ll need to fast for most of the night before the test. Only water is usually allowed unless instructed otherwise. Avoid caffeine or sugary drinks, as they can affect results.
What if my glucose levels are consistently high or low?
Consistently high levels may mean diabetes or insulin resistance, while low levels could indicate issues like hypoglycemia (low blood sugar), adrenal problems, or other metabolic disorders. Always discuss your results with your doctor to determine the next steps.
  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