Hemoglobin Measurement, Whole Blood
A hemoglobin measurement in whole blood determines the amount of hemoglobin, the oxygen-carrying protein in red blood cells. It is a core part of a complete blood count and helps evaluate anemia, blood loss, and other blood conditions.
["Hemoglobin measurement shows how well your red blood cells can carry oxygen and is a key screening test for anemia."]
Key facts at a glance
- LOINC
- 109575-1
- Short code
- Hgb H Msmt Bld
- Synonyms
- Hgb H Msmt Bld
- Category
- hematology
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- 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
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What Is Hemoglobin?
Hemoglobin is a protein found inside red blood cells. It binds oxygen in the lungs and carries it to tissues throughout the body, then helps bring carbon dioxide back to the lungs. Measuring hemoglobin tells your care team how much of this oxygen-carrying protein is present in your blood.
Why the Test Is Ordered
Doctors order a hemoglobin measurement to check for anemia (low hemoglobin), to monitor a known blood disorder, to look for blood loss, or as part of a routine complete blood count. It may also be used to help evaluate symptoms such as fatigue, weakness, shortness of breath, or paleness.
How the Sample Is Collected
The test is usually performed on a small sample of whole blood, commonly drawn from a vein in your arm or obtained by a fingerstick. No special preparation is typically required, though your care team will tell you if other tests in the same panel need fasting.
What the Results Mean
Results are compared with a reference range that varies by age, sex, and sometimes pregnancy status. Low hemoglobin can suggest anemia from many causes, such as iron deficiency, blood loss, or chronic illness. High hemoglobin can occur with dehydration, smoking, or certain blood conditions. Your doctor interprets the result alongside other blood counts and your medical history; specific numbers should be discussed with your care team.
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 measurement is one of the most common blood tests and is central to detecting and monitoring anemia. Because hemoglobin levels can be affected by hydration, altitude, smoking, pregnancy, and many diseases, the result is best interpreted together with red blood cell indices and clinical context rather than in isolation.
Short name
Hemoglobin
Frequently asked questions
Do I need to fast for a hemoglobin test?
Can hemoglobin be low without symptoms?
Does a low hemoglobin result always mean I am anemic?
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