Medical Definition of pernicious anemia
: a severe hyperchromic anemia marked by a progressive decrease in number and increase in size and hemoglobin content of the red blood cells and by pallor, weakness, and gastrointestinal and nervous disturbances and associated with reduced ability to absorb vitamin B12 due to the absence of intrinsic factor—called also addisonian anemia
Seen and Heard
What made you want to look up pernicious anemia? Please tell us where you read or heard it (including the quote, if possible).