Blood diseases

There are many types of blood diseases and can be divided into the following categories:

Hemoglobinopanities: A genetic defect results in the abnormal structure of the hemoglobin molecule which is an oxygen-carrying globular protein containing iron in the red blood cells. Sickle cell disease and thalassemia are examples of this type of disease.

Decreased number of cells: This category includes anemias which are categorized by a decreased number of erythrocytes, or red blood cells, the principal means of delivering oxygen from the lungs via the blood to body tissue. Neutropenias are caused by a decrease in the number of white blood cells, or neutrophils, that are part of the immune system. Thrombocytopenia is the disease where there are not enough platelets, the blood cell fragments used in the formation of blood clots.

Increased number of cells: Includes leukocytosis, the opposite of neutropenia in that there are too many white blood cells and thrombocytopenia again, but this time there are too many platelets.

Hematological malignancies: This group is affected by a type of cancer that attacks the blood, bone marrow and lymph nodes. Lymphonas is a cancer that begins in the lymphatic system which is a secondary circulatory system within the body whose job is to collect stray blood plasma and return it to the primary circulatory system. Leukemia is a cancer of the blood characterized by an abnormal proliferation of white blood cells beginning in the bone marrow.

Coagulopathies: This term applies to those diseases in which there is a defect in the mechanism for blood clotting, usually resulting in either excessive bleeding or a lack of clotting. This can be due to a disorder of clotting proteins of which hemophilia is an example or a disorder of platelets which lack an adhesion receptor essential for blood coagulation.

The remaining category includes those not covered elsewhere, including AIDS and malaria.