What is the difference between iron-deficiency anemia and pernicious anemia?

The main difference is that Iron-Deficiency Anemia is caused by lack of iron, and therefore low haemaglobin levels. Pernicious anamia is caused by a lack of vitimin B12 which aids the production and growth of red blood cells, therefore lowering the haemaglobin level, and both would have a lowered hematocrit level.