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Glucose in Serum or Plasma (Mass Concentration)

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

This test measures the amount of glucose (sugar) in your blood drawn from a vein or capillary. Glucose is the primary energy source for your body’s cells.

Quick summary

["Your blood sugar levels help manage energy and prevent conditions like diabetes."]

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

Key facts at a glance

LOINC
74351-8
Short code
Glucose ?Tm Ur-sCnc
Synonyms
Glucose ?Tm Ur-sCnc
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

What Is Glucose Testing Used For?

Blood glucose tests are commonly used to monitor blood sugar levels, diagnose diabetes or prediabetes, assess how your body responds to treatments like insulin, and check for conditions like hypoglycemia (low blood sugar). They may also be part of routine check-ups or screening for metabolic disorders.

How Is This Test Performed?

A healthcare provider will draw blood from a vein in your arm or, in some cases, from a small puncture on your fingertip. The blood sample is sent to a lab where it is analyzed to determine glucose concentration.

What Does a Glucose Test Tell You?

The test result indicates the current level of glucose in your blood. While specific reference ranges vary by lab, higher or lower than expected levels may signal potential health concerns that need further evaluation.

Common Reasons for Testing

You might need this test if you have symptoms like excessive thirst, frequent urination, unexplained weight changes, fatigue, or recurring infections. It may also be ordered during pregnancy, before surgeries, or as part of ongoing diabetes management.

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.

Clinical Significance: Glucose Levels and Health

Short name

Serum/Plasma Glucose

Frequently asked questions

Why might my glucose test results be important?
High glucose levels over time can damage blood vessels and organs, increasing risks for heart disease, kidney disease, nerve damage, and vision problems. Low glucose levels can cause dizziness, confusion, or fainting. Your doctor will discuss results in the context of your overall health and symptoms.
How often should I get this test?
Frequency depends on your health status. People without diabetes may get baseline tests every few years, while those with diabetes or prediabetes often need testing every 3–6 months or as recommended by their healthcare provider.
What can affect my glucose test results?
Factors like recent meals, exercise, stress, medications (e.g., insulin, steroids), or illness can influence results. Avoid eating or drinking anything except water for at least 8–12 hours before testing if instructed by your provider.
  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