Hemoglobin F Distribution Width in Whole Blood
This test measures the variation in the size of fetal hemoglobin (HbF) molecules in your blood. HbF is a type of hemoglobin found in newborns and some adults with certain blood disorders.
["Understanding your HbF distribution can help identify conditions affecting red blood cell health."]
Key facts at a glance
- LOINC
- 14276-0
- Short code
- Hgb F Dist Bld Kleih Betke-Imp
- Synonyms
- Hgb F Dist Bld Kleih Betke-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
- Method
- kleihauer-betke
- 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 Might Be Ordered
Your healthcare provider may order this test if you have symptoms like anemia, unusual fatigue, or if they suspect conditions like thalassemia, sickle cell disease, or other hemoglobinopathies. It can also be part of prenatal screening or research studies focused on blood disorders.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or hand to draw a small amount of blood, similar to a routine blood test. The process usually takes a few minutes.
What the Results Mean
The test result shows the range of HbF sizes in your blood. A wider distribution might suggest certain blood disorders or genetic conditions affecting red blood cells. Your provider will interpret the results in the context of your overall health and symptoms.
Common Conditions Linked to This Test
This test is often used to diagnose or monitor conditions like thalassemia, sickle cell disease, or other hemoglobin-related disorders. It can also be part of research or specialized screening programs.
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.
Clinical Significance: HbF Distribution Width plays a role in identifying genetic blood disorders by assessing the variability in fetal hemoglobin levels. Abnormal distributions may indicate underlying conditions affecting red blood cell production or structure, guiding treatment decisions.
Short name
HbF Distribution Width
Frequently asked questions
What does a high or low HbF distribution width mean?
How often will I need this test?
Can lifestyle changes affect HbF distribution?
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