Hemoglobin F (HbF) Percentage in Blood

This test measures the amount of fetal hemoglobin (HbF) in your blood. It is done to help diagnose or monitor conditions such as sickle cell disease, beta thalassemia, and certain bone marrow disorders, or to check how well your treatment is working over time.

Doctors may order this test to evaluate conditions like thalassemia, sickle cell disease, or other inherited blood disorders. It can also be used during pregnancy to monitor fetal development or in newborns to diagnose potential genetic blood issues.

A small blood sample is collected, usually from a vein in your arm, by a trained healthcare professional. Little preparation is needed, but you should tell your doctor about any medicines, vitamins, or supplements you take, since some of them may affect your results.

A small blood sample is drawn from a vein, usually in your arm. The blood is processed to separate the hemoglobin types for analysis. This test is typically performed on whole blood.

Before the test, a healthcare professional will explain the procedure and answer your questions. You can usually eat and drink normally unless you are told otherwise. Wear a sleeve that can be rolled up easily, and let the staff know if you have ever felt faint during a blood draw or take blood thinners.

No special preparation is needed, but inform your healthcare provider if you are on blood-thinning medications or have any bleeding disorders. Avoid strenuous activity 24 hours before the test if instructed.

Normal results vary by age. Healthy adults typically have less than 1% HbF, while newborns normally have much higher levels that decrease during the first months of life. Your doctor will compare your value with the reference range and explain what your specific result means for you.

Normal results vary by age and individual health. In newborns, HbF levels are typically high (often 60%–80%). In adults, HbF levels are usually very low (around 0.1%–2%). Your doctor will compare your results to your age and health status.