microcytosis
/ˌmʌɪkrə(ʊ)sʌɪˈtəʊsɪs/Medicine
noun
The presence of an abnormally large number of microcytes in the blood; reduction in the size of red blood cells.
Origin
Late 19th century; earliest use found in Albert Buck (1842–1922). From microcyte + -osis.