Hemoglobin F Percentage in Blood
This test measures the proportion of fetal hemoglobin (HbF) in your red blood cells. HbF is a type of hemoglobin found in babies and some adults with certain blood disorders.
["HbF% helps diagnose or monitor conditions like thalassemia or sickle cell disease."]
Key facts at a glance
- LOINC
- 12710-0
- Short code
- Hgb Fract Bld-Imp
- Synonyms
- Hgb Fract Bld-Imp
- 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
Why This Test Matters
HbF is naturally present in newborns but typically decreases as the body switches to adult hemoglobin. In certain inherited blood disorders, HbF levels remain elevated, which can affect how these conditions are managed. This test helps doctors track disease progression or response to treatment.
What to Expect Before the Test
No special preparation is needed. A simple blood draw from your arm is all that’s required. The test is usually done as part of a routine blood panel or when monitoring a known condition.
How the Test Works
Blood is collected and analyzed to determine the percentage of HbF among all hemoglobin types. Advanced laboratory techniques, such as high-performance liquid chromatography (HPLC), are used to separate and measure the different hemoglobin fractions.
What the Results Mean
Results are expressed as a percentage. While reference ranges vary by lab, higher-than-normal levels may indicate certain blood disorders, while lower levels might suggest conditions like anemia or exposure to certain medications.
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.
◆Associated findings1
Short name
HbF%
Frequently asked questions
What causes abnormal HbF levels?
How often should I get this test?
Can lifestyle changes affect HbF levels?
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