Hematology is the medical discipline that studies blood diseases and cancers originating from bone marrow and deals with their treatments.

What are Blood Diseases?

It is necessary to broadly comprehend functions and structure of blood in order to understand answer to this question. In a healthy adult, the volume of blood is approximately 4 to 5 liters. Blood is a body fluid that transports substances required for nutrition and self regeneration, enables communication by and between organs through certain substances (hormone), fights and defeats foreign bodies and microbes and carries hazardous metabolic waste substances certain organs, such as lungs and kidneys, to excrete thereof.

Blood contains minerals, nutrients, hormones, and proteins that are required for cell proliferation and self-regeneration as well as other proteins that keep blood in liquid phase under normal circumstances, but produce clots in case of an injury along with blood cells and toxic metabolic waste products of organs. There are three types of cells in blood: red blood cells (erythrocytes), white blood cells (leukocyte) and platelets, which function to transfer oxygen and carbon dioxide to/from cells, defend the body against microbes and hazardous agents and enables coagulation in case of bleeding, respectively. Hemoglobin is the molecule that helps transport of oxygen and carbon dioxide by red blood cells. Blood cells are produced by stem cells in the bone marrow and they are broken down and destructed after a certain period. Since these cells are continuously produced by bone marrow, the number of blood cells is kept constant within certain limits. Lymph nodes, thymus and spleen collaborate with the white blood cells in order to protect the body against microbes and harmful agents (immune system). Lymph nodes are small organs that recruit a certain member of white blood cells, called lymphocytes, to fight microbes. Thymus gland also has a similar duty.

Major group of diseases the hematology department deals with are summarized below:

• 1. Abnormal production of blood cells or hemoglobin in bone marrow (various types of anemia, leukopenia and thrombocytopenia)
• 2. Destruction of blood cells earlier than usual life span (hemolytic anemia, ITP, etc.)
• 3. Dysfunctions of blood cells (sickle cell anemia, various dysfunctions, etc.)
• 4. Impaired blood clotting (hemophilia, von Willebrand disease, etc.)
• 5. Unnecessary coagulation of blood in the vascular system (thrombosis, pulmonary thromboembolism, thrombophlebitis, etc.)
• 6. Cancerous transformation of bone marrow cells and lymph node cells (leukemia, lymphomas, myeloma, etc.)