(d) Chronic exhausting diseases, as heart disease, chronic nephritis, cirrhosis of the liver, and gastro-intestinal diseases, especially when associated with atrophy of gastric and duodenal glands. The last may give an extreme anemia, indistinguishable from pernicious anemia.
(e) Chronic poisoning, as from lead, arsenic, and phosphorus.
(f) Hemorrhage—either repeated small hemorrhages, as from gastric cancer and ulcer, uterine fibroids, etc., or a single large one.
(g) Malignant tumors: these affect the blood partly through repeated small hemorrhages, partly through toxic products, and partly through interference with nutrition.
(h) Animal Parasites.—Some cause no appreciable change in the blood; others, like the Uncinaria and Bothriocephalus latus, may produce a very severe anemia, almost identical with pernicious anemia. Anemia in these cases is probably due both to toxins and to abstraction of blood.
The blood-picture varies with the grade of anemia. Diminution of hemoglobin is the most characteristic feature. In mild cases it is slight, and is the only blood change to be noted. In very severe cases hemoglobin may fall to 15 per cent. Red corpuscles are diminished in all but very mild cases, while in the severest cases the red corpuscle count is sometimes below 2,000,000. The color index is usually decreased.
Although the number of leukocytes bears no relation to the anemia, leukocytosis is common, being due to the same cause.
Stained films show no changes in very mild cases. In moderate cases variations in size and shape of the red cells and polychromatophilia occur. Very severe cases show the same changes to greater degree, with addition of basophilic degeneration and the presence of normoblasts in small or moderate numbers. Megaloblasts in very small numbers have been encountered in extremely severe cases. Blood-plaques are usually increased.
2. Primary Anemia.—The commonly described varieties of primary anemia are pernicious anemia and chlorosis, but splenic anemia may also be mentioned under this head.
(1) Progressive Pernicious Anemia.—It is frequently impossible to diagnose this disease from the blood examination alone. Severe secondary anemia sometimes gives an identical picture. Remissions, in which the blood approaches the normal, are common. All the clinical data must, therefore, be considered.