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Hemoglobin F concentration in whole blood

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of fetal hemoglobin (HbF) in your blood. HbF is a type of hemoglobin found in babies and some adults with certain blood disorders.

Quick summary

["HbF levels can help diagnose or monitor conditions like thalassemia or sickle cell disease."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
33517-4
Short code
Hgb Fld Ql
Synonyms
Hgb Fld Ql
Category
hematology
Sample
serum
Container
Red-top tube (SST)
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
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 is this test done?

Your healthcare provider may order this test to check for genetic blood disorders, monitor treatment progress, or assess fetal development during pregnancy.

What does a result mean?

Results are interpreted by your doctor based on your medical history and symptoms. Higher-than-normal levels may suggest genetic blood conditions, while lower levels could indicate certain blood disorders or pregnancy-related changes.

How is the test performed?

A small blood sample is taken from a vein, usually in your arm. The sample is then analyzed in a lab to measure HbF levels.

What should I expect before the test?

No special preparation is needed, but inform your doctor about any medications or health conditions you have.

Reference range

Adult males: 13.5-17.5 g/dL; Females: 12.0-16.0 g/dLN/A

Specimen: serum

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

Hemoglobin F (HbF)

Frequently asked questions

What are normal HbF levels?
Normal HbF levels vary widely and are not universally standardized. Your doctor will compare your results to your specific medical context.
How often should I get this test?
Frequency depends on your medical needs. Your doctor will determine how often this test should be repeated based on your diagnosis and treatment plan.
Does this test hurt?
The blood draw may cause a slight pinch or discomfort, but it usually doesn’t last long. Most people feel fine afterward.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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