You need to give more details because high levels of hemoglobin f can occur in many diseases. Visit your family doctor to see if this is anything serious.
Well there are diseases that are hereditary and acquired hemoglobin F levels. The hereditary ones are: sickle cell anemia, and Beta thalassemia and Herediatary Persistance of Fetal Hemoglobin and the Acquired ones are:
paroxysmal nocturnal hemoglobinuria, aplastic anemia, thyrotoxicosis hepatoma and choriocarcinoma. Are you from the mediterranean originally or is your family? Are you African American? Did you have a complete blood count done? How high was the hemoglobin F level? Do you feel tired all the time or bleed anywhere?