Hematology

Hematology is a branch of physiology and biology that is concerned with the study of human blood, the human organs concerned with blood, and also diseases of the blood. It also involves a study of the etiology, treatment, prognosis, and prevention of blood diseases, with work carried out by medical professionals known as hematologists. The word hema comes from the Greek word for “blood,” with logos from the Greek meaning “study.”

As a basic medical science, hematology is concerned with dealing with blood, blood cells, and blood vessels. This involves working with blood tests, blood poisoning, venipunctures, and related issues. It also is concerned with other related aspects of medicine such as dealing with problems concerned with the reticuloendothelial system, including bone marrow, the spleen, liver complaints, and also problems with the lymphatic system. Following the success of blood transfusions since the 17th century, hematology has become heavily concerned with ensuring that transfusions are done as safely as possible. This involves ensuring that the blood plasma from the donor is free of infection or disease, and that it has been stored properly and categorized into the correct group. This has become particularly important from the mid-1980s with the problems over HIV-infected blood, and later with blood which may be infected with bovine spongiform encephalopathy (“mad cow disease”) or other related complaints.

In addition to mainstream hematology, there are also specialities such as dealing with bleeding disorders including hemophilia, treating hematological malignancies including leukemia and lymphoma, and also treating hemoglobinopathies. There are a number of different classes of hematologic diseases: hemoglobinopathies, anemias, problems involving a decreased number of blood cells, myeloproliferative disorders (with an increased number of cells), hematological malignancies, coagulopathies, and other miscellaneous issues.

The study of hemoglobinopathies involves covering areas where there is a congenital abnormality of the hemoglobin molecule or in the rate of hemoglobin [Page 824]synthesis. This includes sickle-cell diseases which come from genetic disorders of sickle hemoglobin. Other related diseases include thalassemia, an inherited disease affecting red blood cells; and methemoglobinemia which is characterized by a high level of methemoglobin in the blood.

Hematology involves treatment, prognosis, and prevention of diseases by testing blood and blood cells.

With anemias, there is a wide range of potential diseases ranging from some that result from an iron deficiency in the body—often preventable by taking iron supplements and/or eating more red meat, especially kidney. Megaloblastic anemia comes from a B12 deficiency of a folate deficiency, the latter being a particularly important issue for pregnant women. There are also a large number of diseases involving the destruction of red blood cells, collectively called Hemolytic anemias. A number of these are genetic, but others might be induced by drugs, especially a high dose of penicillin. Some are concerned with the membrane of red blood cells, while others are more concerned with their metabolism or direct physical damage to them. Mention should also be made of aplastic anemia whereby bone marrow does not produce enough cells to replenish blood cells in the body. Varieties of this disorder include Fanconi anemia, named after the Swiss pediatrician Guide Fanconi; Diamond-Blackfan anemia, a congenitcal erythroid aplasia; and the acquired pure red cell aplasia.

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