These anemias refer to destruction within the bloodstream of the red blood cells.
They may be due to congenital or hereditary disorders which result in defects in the production of red blood cells and/or hemoglobin. As the red blood cells are destroyed, part of the hemoglobin is released from these cells and the bile pigment (bilirubin) formed leads to an increase in the bilirubin level in the blood. This eventually gives a yellowish color to the skin called jaundice. In severe, chronic, hemolytic anemias, there may also be an accumulation of iron-containing pigment in the body tissues. leading to an enlargement of the liver and a characteristic gray-green discoloration of the skin.
In some of these anemias the spleen, which is the main organ for the destruction of the blood, is often enlarged, and one may be able to feel its outlines in the abdomen.