Glucose (Serum) – Mass Concentration
This test measures the amount of glucose (sugar) in your blood drawn from a vein. It helps assess how well your body is using sugar for energy and managing blood sugar levels.
["A glucose test is often used to check for diabetes or other blood sugar disorders."]
Key facts at a glance
- LOINC
- 58866-5
- Short code
- GH sp42 SerPl-mCnc
- Synonyms
- GH sp42 SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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 healthcare provider may order this test if you have symptoms like excessive thirst, frequent urination, unexplained weight changes, fatigue, or if you have a family history of diabetes. It may also be part of routine check-ups, especially for people at higher risk of blood sugar issues.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast (not eat or drink anything except water) for 8–12 hours before the test if it’s part of a fasting blood sugar check. Wear comfortable clothing and bring any medications you’re currently taking.
During the Test
A healthcare professional will insert a small needle into a vein in your arm to draw blood. You may feel a slight pinch or sting, but it only takes a few minutes. The blood sample is then sent to a lab for analysis.
What the Results Mean
Results are typically reported in milligrams per deciliter (mg/dL). Low or high glucose levels can indicate conditions like hypoglycemia (low blood sugar) or hyperglycemia (high blood sugar), which may require further evaluation or treatment.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Serum Glucose
Frequently asked questions
Glucose levels are critical for diagnosing diabetes, monitoring blood sugar control in people with diabetes, and assessing metabolic health. Persistently high or low levels can lead to serious complications, including nerve damage, heart disease, or kidney problems.
If your results are outside the typical range, your doctor may ask for follow-up tests, such as a fasting glucose test or hemoglobin A1c, to better understand your blood sugar trends. They may also recommend lifestyle changes, medications, or referrals to a specialist.
If your test is part of a fasting check, avoid food and liquids (except water) for 8–12 hours beforehand. For non-fasting tests, follow your doctor’s instructions—some may allow small amounts of water or clear liquids.
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