Skip to content

Glucose, Serum or Plasma (Mass Concentration)

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

This test measures the amount of glucose, a type of sugar, in your blood. It helps doctors check how well your body is using sugar for energy and managing conditions like diabetes.

Quick summary

["Glucose levels help monitor blood sugar control and detect potential issues early."]

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

Key facts at a glance

LOINC
12641-7
Short code
Glucose 7h p chal SerPl-mCnc
Synonyms
Glucose 7h p chal 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 Is This Test Done?

Your doctor may order this test to diagnose or monitor diabetes, check for high or low blood sugar, evaluate liver or kidney function, or assess metabolic health. It’s also used before surgeries or during pregnancy to ensure stable blood sugar levels.

What to Expect Before the Test

No special preparation is needed for this test. If it’s a fasting test, you’ll typically fast for 8–12 hours before the draw. For non-fasting tests, you can eat and drink normally. Avoid smoking or caffeine right before the test.

How the Test Is Performed

A healthcare provider will collect a blood sample from a vein in your arm using a small needle. You may feel a brief pinch, but the procedure is quick and usually painless. The sample is sent to a lab for analysis.

What the Results Mean

Results are compared to standard ranges, but your doctor will interpret them based on your health history and symptoms. High or low glucose levels can signal diabetes, hormonal imbalances, or other conditions that require medical attention.

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 causes abnormal glucose levels?
Abnormal glucose levels can result from diabetes (high or low), poor diet, stress, illness, certain medications, or hormonal imbalances. If your results are outside the expected range, discuss them with your doctor to explore possible causes.
How often should I get this test?
Your doctor will determine how often you need this test based on your health needs. For people with diabetes, tests may be done more frequently (e.g., every 3–6 months) to track progress and adjust treatments. Others may need it less often.
Can lifestyle changes affect glucose test results?
Yes, diet, exercise, and hydration can influence glucose levels. If you’ve made recent lifestyle changes, inform your doctor before interpreting results. Fasting status also matters—always follow your doctor’s instructions for timing.
  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