Hematology is a science that includes the study of etiology, diagnosis, treatment, prognosis and prevention of blood diseases and organs hemolinfo producers. Includes the study of the cell pack, the profile or the blood condition, which are the red blood cell count (or hematocrit value), leukocyte count, hemoglobin determination, the Erythrocyte Sedimentation Rate (ESR), and leukocyte count (WBC differential).