Glucose, Serum (Substance Concentration)
This test measures the amount of glucose, a type of sugar, in your blood serum. It helps doctors assess how well your body is using glucose for energy and managing blood sugar levels.
["A glucose test helps check for diabetes, blood sugar control, or other metabolic conditions."]
Key facts at a glance
- LOINC
- 45054-4
- Short code
- Glucose 12 PM SerPl-sCnc
- Synonyms
- Glucose 12 PM 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 This Test Is Done
Your doctor may order a glucose test to diagnose or monitor conditions like diabetes, prediabetes, or to check for signs of high or low blood sugar. It can also be used during pregnancy (to screen for gestational diabetes) or before certain surgeries.
What to Expect Before the Test
For this test, you’ll typically provide a blood sample from a vein in your arm. No special preparation is needed unless your doctor instructs otherwise, such as fasting before the test (common for fasting glucose tests).
What the Test Results Mean
Results are usually reported as a concentration of glucose in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Your doctor will interpret the results based on your health history and specific clinical context.
Common Reasons for Abnormal Results
High glucose levels may indicate diabetes, poor insulin function, or other metabolic disorders. Low levels could suggest insulin overdose, severe dehydration, or other conditions. Always discuss results with your healthcare provider.
Reference range
Fasting: 70-100 mg/dLN/A
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 Testing Plays a Key Role in Diagnosing and Managing Diabetes and Related Conditions. Elevated or consistently low glucose levels can signal underlying health risks, including nerve damage, kidney issues, or cardiovascular problems. Regular monitoring helps prevent complications and guides treatment plans.
Short name
Glucose Level
Frequently asked questions
How often should I get a glucose test?
What does a normal glucose level mean for my health?
Can lifestyle changes affect glucose test results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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