Skip to content

Glucose, Serum or Plasma Concentration

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

This test measures the amount of glucose (sugar) in your blood drawn from either your vein or a fingerstick.

Quick summary

["Your blood sugar level helps monitor diabetes and other conditions affecting glucose metabolism."]

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

Key facts at a glance

LOINC
59812-8
Short code
Glucose 11 AM SerPl-sCnc
Synonyms
Glucose 11 AM SerPl-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 order glucose tests to check for diabetes, monitor blood sugar control in people with diabetes, or evaluate symptoms like excessive thirst, frequent urination, or unexplained weight changes. It may also be used to diagnose conditions like hypoglycemia (low blood sugar) or to assess metabolic health.

How Is the Test Performed?

A healthcare provider will collect a blood sample—either from a vein in your arm or a small puncture on your finger—using a sterile needle. The sample is sent to a lab for analysis.

What Does the Test Result Mean?

Results are typically reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). While reference ranges vary by lab, high or low values may indicate diabetes, prediabetes, or other metabolic issues. Your doctor will interpret results in the context of your overall health.

Common Reasons for Testing

Glucose tests are commonly done during routine check-ups, before surgeries, or to screen for diabetes risk. They may also be part of a broader metabolic panel or during pregnancy (e.g., gestational diabetes screening).

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.

◆Associated findings1

Short name

Glucose Level

Frequently asked questions

What Are My Next Steps If My Result Is Abnormal?
If your glucose level is outside the expected range, your doctor may recommend follow-up tests, lifestyle adjustments (like diet or exercise), or medication to manage blood sugar. Persistently high or low levels may require further evaluation by a healthcare provider.
How Often Should I Get This Test?
Frequency depends on your health status. People without diabetes may test every few years, while those with diabetes typically check every 3–6 months or as directed by their doctor.
Can I Eat or Drink Before the Test?
For fasting glucose tests, avoid food and drink (except water) for 8–12 hours before the procedure. If your test is not fasting-based, follow your doctor’s instructions to ensure accurate results.
  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