Glucose in Serum or Plasma (24-Hour Urine Collection)

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

This test measures the amount of glucose (sugar) in your blood or urine over a 24-hour period, which helps assess how well your body manages blood sugar levels.

Quick summary

["Understanding your glucose balance over time can help identify diabetes or other metabolic conditions."]

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

Key facts at a glance

LOINC: 50753-3
Short code: GH 15M p Ins IV SerPl-mCnc
Synonyms: GH 15M p Ins IV SerPl-mCnc
Category: hormone
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 they suspect diabetes, prediabetes, or another condition affecting blood sugar control. It can also help monitor long-term glucose levels in people with known diabetes or other metabolic disorders.

What to Expect Before the Test

For the urine portion, you’ll collect all urine for a full 24-hour period in a special container. For the serum/plasma portion, a blood sample will be taken from a vein in your arm. Follow any specific instructions your healthcare provider gives you, such as fasting or dietary restrictions.

How the Test Works

The test measures glucose concentration in either your blood serum/plasma or urine over a full day. The urine test involves collecting all urine produced, while the blood test measures glucose levels at a single point in time (though often part of a broader metabolic panel).

What the Results Mean

Results from the serum/plasma portion will show a single glucose measurement, while the urine portion reflects total glucose excreted over 24 hours. Elevated results may indicate diabetes or poor glucose regulation, while normal results suggest healthy blood sugar control.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Frequently asked questions

What questions do I have about this test?

This test helps diagnose diabetes by checking for consistently high blood sugar levels. It also helps monitor long-term glucose management in people with diabetes or metabolic disorders. If your results are abnormal, your doctor may recommend further testing or adjustments to your treatment plan.

How often should I get this test?

The frequency depends on your health condition. People without diabetes may get this test occasionally as part of routine check-ups, while those with diabetes or metabolic disorders may need it more regularly, often every few months.

Can I eat or drink before this test?

For the serum/plasma portion, you may need to fast before the blood draw. For the urine portion, you’ll collect all urine for 24 hours without restrictions, but avoid excessive sugar intake during that time if instructed.

Sources

1
MedlinePlus — Laboratory TestsSource
2
Lab Tests OnlineSource
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