Skip to content

Glucose, Serum or Plasma (Mass Concentration)

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

This test measures the amount of glucose (sugar) in your blood, typically drawn from a vein or collected in a tube for serum or plasma analysis. Glucose is a key energy source for your body.

Quick summary

["Knowing your glucose levels helps monitor blood sugar balance, especially important for managing diabetes or other metabolic conditions."]

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

Key facts at a glance

LOINC
48994-8
Short code
Glucose 6 AM SerPl-mCnc
Synonyms
Glucose 6 AM SerPl-mCnc
Category
glucose
Sample
serum
Container
Red-top tube (SST)
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
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 It’s Done

Doctors order glucose tests to check for conditions like diabetes, hypoglycemia (low blood sugar), or to monitor treatment progress. It may also be used during pregnancy, before surgeries, or to assess kidney or liver function.

What to Expect

A healthcare provider will insert a small needle into your arm to draw blood. You may feel a brief pinch, but it usually doesn’t cause discomfort. The blood is sent to a lab for analysis.

How Results Are Interpreted

Results are compared to general reference ranges, though exact values can vary by lab. High or low readings may prompt further testing or adjustments to your care plan.

Common Reasons for Testing

Glucose tests are often done if you have symptoms like excessive thirst, frequent urination, fatigue, or unexplained weight changes. They’re also part of routine check-ups for high-risk groups.

Reference range

Fasting: 70-100 mg/dLN/A

Specimen: serum

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.

This test plays a critical role in diagnosing and managing blood sugar disorders. Abnormal results may signal diabetes, prediabetes, or other metabolic issues that require lifestyle changes, medications, or close monitoring.

Short name

Glucose Level

Frequently asked questions

What does a ‘fasting’ glucose test mean for my results?
A fasting test means you should avoid eating or drinking (except water) for at least 8 hours before the blood draw. This helps provide a more accurate measure of your baseline blood sugar levels.
Can diet or exercise affect my glucose test results?
Yes, eating or exercising before testing can influence results. Follow your healthcare provider’s instructions to ensure reliable outcomes, especially if you’re managing diabetes or prediabetes.
How often should I get a glucose test?
Frequency depends on your health status. People with diabetes typically check levels more often (e.g., monthly or as directed by their doctor), while others may need testing less frequently, such as annually or as advised.
  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