Introduction: Thyroid hormones regulate hematopoiesis and as a result hematological  abnormalitites can occur in thyroid dysfunctions. But these are rarely studied and we attempted to evaluate hematological profile in thyroid dysfunction. 

Materials and Methods: A case- control, cross sectional study was performed on 30 normothyroid, hypothyroid and hyperthyroid patients. The thyroid profile values were compared with the hematological profile and analysed using SPSS software.

Results: Erythrocyte sedimentation rate (ESR) and hematocrit showed significant statistical difference (p < 0.05) between control and both hypothyroid and hyperthyroid groups. Hemoglobin showed significant decrease in hypothyroid group when comparedwith controls. There was a significant increase in red cell distribution width (RDW) in hypothyroid patients when compared with controls.

Conclusion: Hypothyroidism can result in increase in MCV and RDW. Hence, hypothyroid patients should be investigated for red cell indices and RDW. Contradictory to this, patients with unexplained refractory anaemia with increase in MCV and RDW should be investigated with thyroid profile to rule out thyroid dysfunction. This will help in early diagnosis, intervention and thus avoiding the complications.

Keywords: Hematological Profile; Thyroid Function Test; Thyroid Dysfunction; RDW.