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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, a type of sugar, in your blood serum or plasma. It helps assess your blood sugar levels.

Quick summary

["This test checks your blood sugar, which is important for managing diabetes and other conditions."]

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

Key facts at a glance

LOINC
34061-2
Short code
GH pre/p Arg SerPl-mCnc
Synonyms
GH pre/p Arg SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 This Test Is Done

Your healthcare provider may order this test to monitor blood sugar levels, diagnose diabetes, evaluate how your body responds to treatments like insulin, or check for conditions like hypoglycemia (low blood sugar). It can also be used during pregnancy to screen for gestational diabetes.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast (not eat or drink anything except water) for 8–12 hours before the test if it’s part of a fasting blood sugar check. Otherwise, you can eat and drink normally.

How the Test Is Performed

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but the procedure is quick. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are typically reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). While reference ranges vary by lab, higher or lower levels than expected may signal diabetes, prediabetes, or other metabolic issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal glucose levels can indicate diabetes, insulin resistance, or other metabolic disorders. Persistently high or low levels may require further testing, lifestyle adjustments, or medical interventions to prevent long-term complications like nerve damage, heart disease, or kidney problems.

Short name

Serum/Plasma Glucose

Frequently asked questions

What causes blood sugar levels to change?
Blood sugar levels can be affected by diet, physical activity, stress, medications (like insulin or diabetes drugs), illness, or hormonal changes. If you notice frequent fluctuations, discuss them with your healthcare provider.
How often should I get this test?
Frequency depends on your health status. People with diabetes may need tests every few months, while others may only need them once a year or as recommended by their provider.
Can I eat or drink before the test?
If fasting is required (e.g., for a fasting glucose test), avoid food and liquids except water for 8–12 hours beforehand. For non-fasting tests, eating and drinking normally is fine unless instructed otherwise.
  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