Glucose, Serum or Plasma (High-Pressure Liquid Chromatography)
This test measures the amount of glucose (sugar) in your blood, drawn from either serum or plasma. Glucose levels help assess how your body uses energy and can indicate risks for conditions like diabetes.
["Glucose levels reflect your body’s ability to process energy and may signal diabetes or other metabolic concerns."]
Key facts at a glance
- LOINC
- 1504-0
- Short code
- Glucose 1h p 50 g Glc PO SerPl-mCnc
- Synonyms
- Glucose 1h p 50 g Glc PO 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 healthcare provider may order this test to check for diabetes, monitor blood sugar control in people with diabetes, diagnose or manage conditions like hypoglycemia (low blood sugar), or evaluate metabolic health. It can also help assess how well medications are working for blood sugar management.
What to Expect Before the Test
No special preparation is usually needed, but 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. If you’re not fasting, you can eat and drink normally. Let your provider know about any medications you’re taking, as some may affect results.
During the Test
A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but the process is quick. The blood sample is then sent to a lab for analysis using high-performance liquid chromatography (HPLC), which separates and measures glucose with high precision.
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, lower or higher-than-normal levels may signal potential health issues that need 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.
Elevated glucose levels may indicate diabetes, prediabetes, or insulin resistance. Persistently low levels can cause fatigue, dizziness, or confusion. Regular monitoring helps prevent complications like nerve damage, kidney disease, or heart problems. Your provider will discuss results in the context of your overall health and treatment plan.
Short name
Glucose Level
Frequently asked questions
What causes glucose levels to change?
How often should I get this test?
Can lifestyle changes affect my 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