Branch of medicine concerned with the nature, function, and diseases of the blood. It covers the cellular and serum composition of blood, the coagulation process, blood-cell formation, hemoglobin synthesis, and disorders of all these. Marcello Malpighi, in the 17th century, was the first to examine red blood cells (erythrocytes). In the 18th century, the British physiologist William Hewson (1739–74) examined the lymphatic system and blood clotting. In the 19th century, the bone marrow was recognized as the site of blood-cell formation, and diseases of the blood such as anemia and leukemia were identified. In the early 20th century, the ABO blood-group system was discovered and the role of nutrition in blood formation was studied. Post-World War II studies have delved further into the nature of blood diseases and improved treatments and have examined hemoglobin synthesis and the role of platelets in blood coagulation.

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Hematology (American English) or haematology (British English) is the branch of biology (physiology), pathology, clinical laboratory, internal medicine, and pediatrics that is concerned with the study of blood, the blood-forming organs, and blood diseases. Haematology includes the study of etiology, diagnosis, treatment, prognosis, and prevention of blood diseases. The lab work that goes into the study of blood is performed by a Medical Technologist.

Blood diseases affect the production of blood and its components, such as blood cells, hemoglobin, blood proteins, the mechanism of coagulation, etc.

Physicians specialized in hematology are known as haematologists. Their routine work mainly includes the care and treatment of patients with haematological diseases, although some may also work at the haematology laboratory viewing blood films and bone marrow slides under the microscope, interpreting various haematological test results. In some institutions, haematologists also manage the haematology laboratory. Physicians who work in haematology laboratories, and most commonly manage it, are pathologists specialized in the diagnosis of haematological diseases, referred to as haematopathologists. Haematologists and haematopathologists generally work in conjunction to formulate a diagnosis and deliver the most appropriate therapy if needed. Haematology is a distinct subspecialty of internal medicine, separate from but overlapping with the subspecialty of medical oncology. Haematologists may specialise further or have special interests, for example in:

• treating bleeding disorders such as hemophilia and idiopathic thrombocytopenic purpura
• treating haematological malignacies such as lymphoma and leukemia (onco haematology)
• treating haemoglobinopathies
• in the science of blood transfusion and the work of a blood bank

''(Hema- comes from the Greek word "`'aima" meaning "blood", -ology means study of.)

Common basic clinical hematology tests

In a clinical laboratory the hematology department performs numerous different tests on blood. The most commonly performed test is the complete blood count (CBC) also called full blood count (FBC), which includes; white blood cell count, platelet count, hemoglobin level and several parameters of red blood cells. Coagulation is a sub-speciality of hematology; basic general coagulation tests are the prothrombin time (PT) and partial thromboplastin time (PTT). Another common hematology test in the erythrocyte sedimentation rate (ESR).

In a blood bank the Coombs test is the most commonly performed test.

Hematology as basic medical science

• Blood
• Venous blood
• Venipuncture
• Haemopoiesis
• Blood tests
• Cord blood
• Red blood cells
• Erythropoiesis
• Erythropoietin
• Iron metabolism
• Haemoglobin
• Glycolysis
• Pentose phosphate pathway
• Reticuloendothelial system
• Bone marrow
• Spleen
• Liver
• Lymphatic system
• Blood transfusion
• Blood plasma
• Blood bank
• Blood donors
• Blood groups
• Haemostasis
• Coagulation
• Vitamin K
• Complement system
• Immunoglobulins

Classification of hematologic diseases

Major categories of hematologic disease include:

• Hemoglobinopathies (congenital abnormality of the hemoglobin molecule or of the rate of hemoglobin synthesis)
• Anemias (lack of red blood cells or hemoglobin)
• Hematological malignancies
• Coagulopathies (disorders of bleeding and coagulation)

Tests

Tests used in the investigation of hematological problems include:

• Full blood count
• Erythrocyte sedimentation rate (ESR)
• Blood film
• Bone marrow examination
• Coombs test
• Diascopy
• serum Ferritin level
• Vitamin B12 and Folate levels
• Prothrombin time
• Partial thromboplastin time
• Protein electrophoresis
• Hemoglobin electrophoresis
• D-dimer
• EOS

Treatments

Treatments include:

• Diet advice
• Oral medication - tablets or liquid medicines
• Anticoagulation therapy
• Intramuscular injections (for example, Vitamin B12 injections)
• Blood transfusion (for anemia)
• Venesection also known as therepeutic phlebotomy (for iron overload or polycythemia)
• Bone marrow transplant (for example, for leukemia)
• Chemotherapy (for example, for leukemia)
• Radiotherapy (in decline, for example, for leukemia)

Alphabetical lists

• Hematologists
• Blood disorders
• Hematology

External links

• American Society of Hematology
• Asia-Pacific Journal of Cancer Therapeutics APJCT
• BloodLine
• Major milestones in history of hematology (PDF)
• Multilingual index
• Extensive Hematology Slide Collection