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Glucose 18-Hour Urine Rate

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

This test measures how much glucose appears in your urine over an 18-hour period, often used to assess how well your body manages glucose (sugar) over time.

Quick summary

["Helps track long-term glucose control in conditions like diabetes."]

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

Key facts at a glance

LOINC
58997-8
Short code
Glucose 18h Ur-mRate
Synonyms
Glucose 18h Ur-mRate
Category
glucose
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
70
Ref high
100
Critical range
50 N/A – 400 N/A
Fasting
true
Population
adult
Sex
all
Age range
18–65 years
CPT
82947
SNOMED
260395008
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test to evaluate how your body handles glucose over an extended period, particularly if you have diabetes or are at risk for complications. It helps determine if your glucose levels are consistently within a healthy range when fasting or during normal daily activities.

How the Test Works

A urine sample is collected over 18 hours. Glucose levels are measured in the urine, reflecting how much sugar your body is excreting. This test is typically done using a specialized urine collection kit provided by your healthcare provider.

What to Expect Before the Test

No special preparation is needed, but you may be asked to follow a standard diet or avoid certain foods/sugars for a short period beforehand. Drink plenty of water unless instructed otherwise.

What to Expect During the Test

You’ll collect urine in a container for 18 hours, usually starting in the morning. The sample is then sent to a lab for analysis. The test is non-invasive and painless.

Reference range

Fasting: 70-100 mg/dLN/A

Specimen: urine

Fasting for 8-12 hours required. Water is permitted. Avoid chewing gum and smoking before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine Glucose Rate (18-hour)

Frequently asked questions

How is this test different from a standard urine glucose test?
This test measures the rate of glucose excretion over an extended period (18 hours), giving a broader picture of how your body handles sugar continuously. Standard urine glucose tests typically check for glucose presence in a single sample or over shorter periods.
What does a high or low result mean?
A high result may signal diabetes, poor insulin function, or kidney problems. A low result could indicate metabolic issues or medications affecting glucose metabolism. Your doctor will interpret results in the context of your overall health and medical history.
Can I eat or drink anything before or during the urine collection?
Yes, but follow your healthcare provider’s instructions. Typically, you may continue a standard diet unless advised otherwise, but avoid excessive sugar intake. Drink water as usual unless specified.
  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