Anemia in Hypothyroidism and Hypoituitarism
Mar
31
Written by:
3/31/2009
In hypothyroidism, anemia is usually mild to moderate and it typically develops slowly. Thyroid hormone regulates the body’s cellular metabolic rate and the tissue’s oxygen requirement. With decreased levels of thyroid hormone, there is a smaller tissue oxygen requirement. The kidneys interpret that as though the body has a more than adequate oxygen-tension. The net result is a decrease in the body’s production of erythropoietin, a chemical needed for the production of red blood cells.
Consequently, red blood cell (erythrocyte) survival is normal although it's production is decreased. With the use of thyroid replacement hormone, anemia slowly remits.
Usually, this causes a macrocytic normochromic anemia, meaning that the red blood cells are slightly larger but with a normal amount of hemoglobin. Occasionally, the anemia can be normocytic and normochromic meaning that the red blood cells are of the normal size. Anemia in hypothyroidism may also be complicated by iron, folic acid, or vitamin B12 deficiency, and the blood picture may reflect those forms of anemia.
In pituitary gland deficiency anemia is typically more severe than that seen in hypothyroidism. In addition, pituitary gland deficiencies are usually accompanied by decreased white blood cell counts. In males, deficiencies in androgen production may be the cause of anemia. Normally, androgens stimulate erythopoiesis (red blood cell production).