Thalassemia (thal-uh-SEE-me-uh) is an inherited blood disorder characterized by less hemoglobin and fewer red blood cells in your body than normal. Hemoglobin is the substance in your red blood cells that allows them to carry oxygen. The low hemoglobin and fewer red blood cells of thalassemia may cause anemia, leaving you fatigued.
If you have mild thalassemia, you may not need treatment. But if you have a more severe form of the disorder, you may need regular blood transfusions. You can also take steps on your own to cope with fatigue, such as choosing a healthy diet and exercising regularly.