Glucose in Whole Blood (Fasting or Random)
This test measures the amount of glucose, a type of sugar, in your blood. It helps doctors check how well your body is using glucose for energy.
["A blood glucose test helps monitor blood sugar levels, which is crucial for managing diabetes and other metabolic conditions."]
Key facts at a glance
- LOINC
- 75402-8
- Short code
- GCDH Mut Anl Bld/T
- Synonyms
- GCDH Mut Anl Bld/T
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order a blood glucose test to diagnose conditions like diabetes, monitor treatment progress, or 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 fasting blood glucose tests, you’ll typically fast for 8–12 hours before the test. Random blood glucose tests can be done at any time. Bring any medications you’re taking and let your healthcare provider know if you have any concerns or conditions that might affect results.
During the Test
A healthcare professional will insert a small needle into a vein in your arm to draw a blood sample. You may feel a slight pinch, but it usually doesn’t cause pain. The blood sample is then sent to a lab for analysis.
What the Results Mean
Results are interpreted based on your medical history and symptoms. High blood glucose levels may indicate diabetes or other metabolic disorders, while very low levels could signal conditions like hypoglycemia or adrenal insufficiency. Your doctor will discuss the results with you in detail.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Blood Glucose
Frequently asked questions
High blood glucose levels over time can damage blood vessels and nerves, increasing the risk of complications like heart disease, nerve damage, or kidney problems. Regular monitoring helps prevent these risks and ensures proper management of blood sugar.
How can I prepare for this test? Follow your doctor’s instructions carefully, especially regarding fasting if required. Avoid eating or drinking anything (except water) for the specified period before the test.
Are there any risks or side effects? The most common side effect is a slight bruise or minor discomfort at the injection site. Rarely, a reaction to the needle or infection may occur, but these are uncommon.
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