It is not just Thyroid UK/HU that says that anaemia frequently accompanies thyroid disease!
Pol Arch Intern Med. 2017 Mar 28. doi: 10.20452/pamw.3985. [Epub ahead of print]
Anemia in thyroid diseases.
Szczepanek-Parulska E, Hernik A, Ruchała M.
Anemia is a frequent, although often underestimated, clinical condition accompanying thyroid diseases. In spite of the fact that anemia and thyroid dysfunction often occur simultaneously, the causative relationship between these two disorders remains ambiguous. Thyroid hormones stimulate erythrocytes precursors proliferation directly, as well as via erythropoietin production enhancement, whereas iron-deficient anemia negatively influences thyroid hormonal status. Thus, different forms of anemia might emerge in the course of thyroid dysfunction. In fact, normocytic anemia is most common, while macrocytic or microcytic anemia occur less frequently. Anemia in hypothyroidism might result from bone marrow depression, decreased erythropoietin production, comorbid diseases, or concomitant iron, vitamin B12 or folate deficiency. Altered iron metabolism and oxidative stress may contribute to anemia in hyperthyroidism. The risk of anemia in autoimmune thyroid disease (AITD) may be posed by pernicious anemia and atrophic gastritis, celiac disease, autoimmune hemolytic syndrome, or rheumatic disorders. The simultaneous occurrence of anemia and thyroid disease, as well as their close relation, make the diseases an important clinical problem. The aim of the study is to provide a comprehensive review summarizing data on the prevalence, potential mechanisms, and therapy of anemia in the course of thyroid diseases from the clinical and pathogenetic perspective. Thyroid dysfunction and autoimmune thyroid disease should be considered in differential diagnosis of treatment-resistant or refractory anemia, as well as in case of increased red blood cell distribution width (RDW). Of note is that the presence of AITD itself, independently from thyroid hormonal status, might affect hemoglobin level.
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