This document provides an overview of various types of leukemia, including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and infantile leukemia. It discusses the classification, signs and symptoms, diagnosis, and management of these leukemias. Specific hematologic emergencies that can occur in leukemia patients are also reviewed, such as leukostasis, tumor lysis syndrome, spinal cord compression, and respiratory distress syndrome.