The symptoms of thalassemia depend on the genetic defect and its severity. The more severe the genetic defect, the less hemoglobin that is produced and the more severe the anemia that results. Thalassemia minor may not cause any symptoms. If it does, the most common symptom is long-term, mild anemia.
Someone with thalassemia major usually has severe hemolytic disease. This means that the red blood cells are constantly being destroyed. This occurs faster than the body can replace them. Thalassemia major is usually diagnosed by 1 year of age. The symptoms of thalassemia major may include: