Anemia pathophysiology
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Anemia main page |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
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Overview
Specific Anemias
- Anemia of prematurity occurs in premature infants at 2 to 6 weeks of age and results from diminished erythropoietin response to declining hematocrit levels
- Fanconi anemia is an hereditary disorder or defect featuring aplastic anemia and various other abnormalities
- Hemolytic anemia causes a separate constellation of symptoms (also featuring jaundice and elevated LDH levels) with numerous potential causes. It can be autoimmune, immune, hereditary or mechanical (e.g. heart surgery). It can result (because of cell fragmentation) in a microcytic anemia, a normochromic anemia, or (because of premature release of immature red blood cells from the bone marrow), a macrocytic anemia.
- Hereditary spherocytosis is a hereditary defect that results in defects in the RBC cell membrane, causing the erythrocytes to be sequestered and destroyed by the spleen. This leads to a decrease in the number of circulating RBCs and, hence, anemia.
- Sickle-cell anemia, a hereditary disorder, is due to homozygous hemoglobin S genes.
- Warm autoimmune hemolytic anemia is an anemia caused by autoimmune attack against red blood cells, primarily by IgG
- Cold agglutinin hemolytic anemia is primarily mediated by IgM
- Pernicious anemia is a form of megaloblastic anaemia due to vitamin B12 deficiency dependent on impaired absorption of vitamin B12.
- Myelophthisic anemia or Myelophthisis is a severe type of anemia resulting from the replacement of bone marrow by other materials, such as malignant tumors or granulomas.
Anemia During Pregnancy
Anemia affects 20% of all females of childbearing age in the United States. Because of the subtlety of the symptoms, women are often unaware that they have this disorder, as they attribute the symptoms to the stresses of their daily lives. Possible problems for the fetus include increased risk of growth retardation, prematurity, intrauterine death, rupture of the amnion and infection.
During pregnancy, women should be especially aware of the symptoms of anemia, as an adult female loses an average of two milligrams of iron daily. Therefore, she must intake a similar quantity of iron in order to make up for this loss. Additionally, a woman loses approximately 500 milligrams of iron with each pregnancy, compared to a loss of 4-100 milligrams of iron with each period. Possible consequences for the mother include cardiovascular symptoms, reduced physical and mental performance, reduced immune function, tiredness, reduced peripartal blood reserves and increased need for blood transfusion in the postpartum period.