ANAEMIA

BLOOD LOSS (RBC loss):

acute

[NB: anaemia evident after restoration of blood volume with fluids other than blood]

chronic

lesions of git with slow bleeding (result in iron-deficiency anaemia)

HAEMOLYSIS (increased destruction of RBC's):

abnormalities of RBC's

hereditary defects:

disorders of membrane:

hereditary stomatocytosis

RBC enzyme deficiency:

others (rarer)

disorders of Hgb synthesis:

decreased globin (thalassaemias)

defective globin (haemoglobinopathies)

acquired membrane defects:

liver disease

extra-corpuscular abnormalities:

antibody-mediated haemolysis:

iso-haemagglutinins (Rhesus and ABO incompatibilities):

erythroblastosis foetalis

auto-antibodies:

associated with collagen disorders, eg. systemic lupus erythematosus

associated with malignancies

mechanical trauma to RBC's (red cell fragmentation syndromes):

cardiac traumatic haemolytic anaemia (prosthetic heart valves)

microangiopathic haemolytic anaemia

infections, eg. malaria

Wilson's disease (oxidative damage by excess copper)

DECREASED RBC PRODUCTION:

disturbances of proliferation / differentiation of stem cells:

aplastic anaemia

pure red cell aplasia

anaemia of renal failure (low erythropoeitin)

congenital dyserythropoietic anaemias (3 types; all rare)

anaemia of endocrine disorders:

hypothyroidism

hypoadrenalism

hypopituitarism

hypogonadism

disturbances of proliferation / maturation of erythroblasts:

defective DNA synthesis

B12 or folate deficiency; megaloblastic anaemia

defective Hgb synthesis:

deficient haem (iron deficiency)

deficient globin (thalassaemias)

unknown or multiple mechanisms:

sideroblastic anaemias

anaemia of chronic infection

marrow infiltration:

carcinomatosis