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Hemoglobin F (Mass Concentration) in Fluid

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

This test measures the amount of fetal hemoglobin (HbF) in your blood. Fetal hemoglobin is a type of hemoglobin found in newborns that later changes as they grow.

Quick summary

["HbF levels can help diagnose or monitor certain blood conditions."]

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

Key facts at a glance

LOINC
33509-1
Short code
Hgb Fld-mCnc
Synonyms
Hgb Fld-mCnc
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

What Is Fetal Hemoglobin?

Fetal hemoglobin (HbF) is a form of hemoglobin that carries oxygen in the blood of a fetus. After birth, most of the hemoglobin in adults switches to a different type called adult hemoglobin (HbA). Measuring HbF helps doctors understand how well this transition is happening or if there are underlying conditions affecting it.

Why Might You Need This Test?

This test may be ordered to evaluate conditions like beta-thalassemia, sickle cell disease, or other blood disorders that involve abnormal hemoglobin production. It can also be used to monitor certain blood cancers or genetic blood disorders.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The blood is then processed to measure the concentration of fetal hemoglobin using a specialized laboratory technique.

What Do Results Mean?

Results are compared to expected ranges for adults and newborns. Higher than normal levels of HbF might indicate certain genetic blood disorders, while lower levels could suggest conditions affecting hemoglobin production or red blood cell health.

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

HbF

Frequently asked questions

What could cause abnormal HbF levels?
Abnormally high levels of HbF can be linked to genetic blood disorders such as beta-thalassemia or sickle cell trait. High levels may also appear in certain types of anemia or after blood transfusions. Abnormally low levels are less common but could be associated with conditions affecting red blood cell production or hemoglobin structure.
How often should I get this test?
The frequency of this test depends on your medical condition and why it was ordered. Your healthcare provider will determine the best schedule based on your specific needs, such as monitoring a known blood disorder or evaluating symptoms.
Can lifestyle changes affect HbF levels?
While lifestyle factors like diet and exercise generally do not directly influence HbF levels, managing underlying conditions (such as anemia or genetic disorders) through recommended treatments can help maintain stable blood health.
  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