Hemoglobin Substance Concentration in Whole Blood (Mass Concentration)
This test measures the amount of hemoglobin, the protein in red blood cells that carries oxygen throughout your body.
["Hemoglobin helps ensure your tissues get enough oxygen, and low or high levels can signal health concerns."]
Key facts at a glance
- LOINC
- 724-5
- Short code
- Hgb Snv-mCnc
- Synonyms
- Hgb Snv-mCnc
- Category
- hematology
- Sample
- fluid
- Container
- Sterile tube
- Units
- N/A
- Ref low
- 12
- Ref high
- 17.5
- Critical range
- 7 N/A – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85018
- SNOMED
- 900000000000003004
- Specimen volume
- 2-5 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h
- Hemolysis max
- 300
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Hemoglobin levels are crucial for diagnosing conditions like anemia (low levels) or polycythemia (high levels). Your doctor may order this test to check for blood disorders, check your response to treatments, or monitor chronic conditions like heart or lung diseases.
What to Expect Before the Test
You may have a simple finger-prick blood draw, or your doctor might use a vein in your arm. No special preparation is usually needed, but let your doctor know about any medications or recent illnesses.
What the Results Mean
Results are compared to a general reference range based on age, sex, and health status. While exact values vary, very low levels may indicate anemia, while very high levels could suggest conditions like dehydration or blood disorders.
Common Conditions Affecting Results
Factors like pregnancy, heavy exercise, or certain medications can influence hemoglobin levels. Chronic illnesses, bleeding, or blood loss can also alter results. Always discuss your full medical history with your provider.
Reference range
Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Hemoglobin levels are a key indicator of red blood cell health and overall oxygen-carrying capacity. Abnormalities can signal anemia, iron deficiency, or other systemic issues requiring further medical evaluation. Your doctor may recommend follow-up tests or treatments based on the results.
Short name
Hemoglobin Level
Frequently asked questions
What causes hemoglobin levels to be too low?
What causes hemoglobin levels to be too high?
How often should I get this test?
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