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Glucose, Plasma or Serum Concentration

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

This test measures the amount of glucose (sugar) in your blood plasma or serum, often checked to monitor blood sugar levels.

Quick summary

["A simple blood test to track blood sugar, useful for diabetes management and general health."]

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

Key facts at a glance

LOINC
14748-8
Short code
Glucose Prt-sCnc
Synonyms
Glucose Prt-sCnc
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 Is This Test Done?

Doctors may order this test to diagnose or manage conditions like diabetes, high or low blood sugar, or to check for metabolic issues. It’s also used during pregnancy to monitor gestational diabetes or before surgeries to assess risk for complications.

How Is the Test Performed?

A small blood sample is taken from your arm, usually by a healthcare professional. The sample is sent to a lab where glucose levels are measured using an enzymatic method, which detects the presence of glucose through chemical reactions.

What Does the Result Mean?

Results are compared to general reference ranges, but individual needs may vary. High levels may indicate diabetes or other metabolic disorders, while very low levels could signal hypoglycemia or other health concerns. Your doctor will interpret results in the context of your medical history and symptoms.

Common Reasons for Testing

This test is commonly requested for routine health checks, diabetes screening, fasting glucose assessments, or to monitor treatment effectiveness for conditions affecting blood sugar.

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.

Chronically elevated or low glucose levels can lead to serious health problems, including nerve damage, heart disease, kidney issues, or complications during pregnancy. Regular monitoring helps prevent these risks and guides treatment decisions, such as medication adjustments or lifestyle changes.

Short name

Plasma/Serum Glucose

Frequently asked questions

What causes abnormal glucose levels?
Abnormal glucose levels can result from conditions like diabetes (either type 1 or type 2), poor diet, stress, infections, certain medications, or hormonal imbalances. Lifestyle factors such as physical activity, smoking, or alcohol consumption may also play a role.
How can I prepare for this test?
For fasting glucose tests, you’ll typically need to avoid eating or drinking (except water) for 8–12 hours before the test. If your doctor specifies a non-fasting test, follow their instructions. Wear comfortable clothing and bring any medications you’re currently taking.
What should I do if I have symptoms like dizziness or shakiness before the test?
If you experience symptoms of low blood sugar (hypoglycemia) before your test, inform your healthcare provider immediately. They may adjust your test timing or instructions to ensure accurate results. Never drive yourself to the lab if you’re feeling unwell.
  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