Background: Thyroid hormones perform cardinal role in every steps of erythropoiesis. These hormones motivates the growth of colonies like erythroid burst forming units (BFU–e) and colony forming units (CFU–e) and Repletion of the Hypoxia Inducible Factor 1is escalated by these hormones of the thyroid gland. They enhance erythropoiesis and they do so by increasing the rate of proliferation of erythroid progenitors (immature) and they also increase erythropoietin secretion by inducing gene expression of erythropoietin. The compactness of erythrocyte 2, 3–Diphospho glycerate also steps up by hormones of the thyroid gland and as the result of which the rate of oxygen delivery increases to every tissues of body. Thus, if there is reduction in the levels of the thyroid hormones, erythropoiesis is affected, leading to changes in RBC count and hemoglobin.

Material and Method: This is a cross sectional study conducted in department of biochemistry which includes 50 newly diagnosed, untreated hypothyroid subjects and 50 healthy euthyroid subjects. The period of this study is from December 2016 to September 2017. The hematological parameters like hemoglobin, RBC count and TSH levels were analyzed by appropriate biochemical tests and statistical software.

Result: It was found in our study that subjects having hypothyroidism had mean Hb level 9.40 gm/dl and mean RBC count as 3.5 millions/cu mm, compared to normal control group having mean Hb 12.41 gm/dl and 4.49 millions/cu mm respectively. Statistically significant difference was obtained between both these study groups with p value <0.001.

Conclusion: Subjects with hypothyroidism have lower levels of hemoglobin and RBC count compared to normal subjects. This is because, hypothyroidism is associated with decreased erythropoiesis, leading to anemia and should be managed to prevent it.