Glucose, Serum
This test measures the amount of glucose (sugar) in your blood drawn from a vein in your arm. It helps doctors check how well your body is using sugar for energy.
["A glucose test helps monitor blood sugar levels, often used in diabetes management."]
Key facts at a glance
- LOINC
- 1513-1
- Short code
- Glucose 20M p .5 g/kg Glc IV SerPl-mCnc
- Synonyms
- Glucose 20M p .5 g/kg Glc IV 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 conditions like diabetes, check for high blood sugar, or assess how your body processes food. It’s also used during pregnancy to screen for gestational diabetes or before surgeries to ensure stable blood sugar levels.
What to Expect Before the Test
No special preparation is needed for this test. You may be asked to fast (not eat or drink) for 8–12 hours before the test if it’s part of a fasting glucose study. Otherwise, you can eat and drink normally. Bring any medications you’re taking to your appointment.
What Happens During the Test?
A healthcare provider will clean the area on your arm with an antiseptic and insert a small needle to draw blood. You may feel a slight pinch, but it usually takes only a few seconds. The blood is then sent to a lab for analysis.
What Does the Test Result Mean?
Results are typically reported as a numerical value representing the concentration of glucose in your blood. While reference ranges vary by lab, lower or higher-than-expected results may signal potential health concerns that require further evaluation by your doctor.
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.
Glucose levels outside normal ranges can indicate diabetes, prediabetes, or other metabolic disorders. High glucose may cause fatigue, frequent urination, or blurred vision, while low glucose (hypoglycemia) can lead to shakiness, dizziness, or confusion. Regular monitoring helps prevent long-term complications like nerve damage or heart disease.
Short name
Glucose Level
Frequently asked questions
How often should I get this test?
What can affect my glucose test results?
What if my test results are abnormal?
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