Sickle cell anemia is cause when normal, healthy red blood cells morph into an oblong crescent moon shape. Because of the abnormal shape, the red blood cell die quicker resulting in a reduced red blood cell count. White blood cells are elevated because they are constantly trying to get rid of the unhealthy red blood cells. Hemoglobin is an oxygen-carrying protein that is mostly found in red blood cells, and with reduced RBC's, hemoglobin is also reduced.
