Anemia 

Anemia occurs when the number of red blood cells or concentrations of hemoglobin are low.  Anemia is the most common disorder of the blood.  Anemia is usually not seen as a sole basis for preventing someone from working.  It is more common for anemia to accompany other medical problems and serve as sign of a chronic disease.  The testimony of a person with anemia will usually involve weakness and feeling tired.  Proof of the fatigue level of the person and the connection to activities they can no longer do is crucial.  The cases involving anemia will almost always turn back to what is causing the anemia.