Glucose, Serum (Concentration)
This test measures the amount of glucose, a simple sugar, in your blood serum. Glucose is your body’s primary energy source and is regulated by hormones like insulin.
["This test helps assess blood sugar levels and identify conditions like diabetes or hypoglycemia."]
Key facts at a glance
- LOINC
- 54257-1
- Short code
- Glucose pre Ins IV SerPl-sCnc
- Synonyms
- Glucose pre Ins IV 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 or other blood sugar disorders. They may also test glucose levels before surgeries, during pregnancy, or if you have symptoms like excessive thirst, frequent urination, or unexplained weight loss.
What to Expect Before the Test
For this test, you’ll have a small needle inserted into your arm or vein to draw blood. If you’re fasting (not eating or drinking except water) for 8–12 hours before the test, your doctor will instruct you accordingly. Avoid smoking or caffeine before the draw.
What Happens During the Test?
The blood sample is collected in a tube and sent to a lab, where it’s analyzed for glucose concentration. Results are typically available within a few hours to a day, depending on the lab.
What the Results Mean
Results are compared to general reference ranges, but your doctor will interpret them in the context of your health history and symptoms. Very high or low glucose levels may signal underlying conditions that need further evaluation.
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.
◆Associated findings1
Short name
Glucose Level
Frequently asked questions
Glucose tests are critical for diagnosing diabetes (both type 1 and type 2), monitoring blood sugar control in people with diabetes, and detecting hypoglycemia (low blood sugar). Abnormal results may prompt additional testing or lifestyle changes.
A normal result typically indicates your blood sugar is within the expected range for your health status, but individual ranges can vary. Your doctor will discuss your specific results with you and may recommend follow-up tests if needed.
Your doctor will determine how often you need this test based on your medical history, symptoms, and treatment plan. For example, people with diabetes may need glucose tests more frequently than others.
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