Correlation Between Thyroid Hormones and Hematological Profiles in Patients with Thyroid Dysfunction
Authors: Prasad K. Ganesha , Babu Senthil Kumar , Khaleeluddin Kouser Banu , Jayakumar Saikarthik , Vendhan K Ezhil 
Published: February 2025

Background: Irregularities in blood cells are recurrently connected with thyroid hormone dysfunction, thyroid hormones such as T3 and T4, play a vital role in blood formation and cellular differentiation and dysregulation that can lead to noteworthy modifications in blood parameters. Aim: Present study aimed to examine the correlation between thyroid dysfunctions, predominantly hyperthyroidism and hypothyroidism, and their impression on haematological parameters. Methods: A cross-sectional study was performed among the 210 individuals from the tertiary care hospital in Dermatology department at Shimoga, Karnataka. Blood samples from individuals were analysed to evaluate thyroid hormone levels along with the haematological parameters. Chemiluminescent immunoassays were used to quantity T3, T4 and TSH levels, while CBC analyser analyse RBC, WBC, haemoglobin (Hb) and other blood indices. Based on the analysis the participants are categorised with Hyperthyroidism group, Hypothyroidism group and Control group. Results: In the study, significant variations were observed in haematological parameters across thyroid conditions. RBC levels were lower in hyperthyroid compared to normal (mean difference: -0.4495, p < 0.01) and higher in hypothyroid compared to hyperthyroid (mean difference: 0.797, p < 0.01). Hb levels were reduced in hyperthyroid (mean difference: -1.4691, p < 0.01) and hypothyroid patients (mean difference: -2.0434, p < 0.01). MCV and MCH were significantly higher in hypothyroid than hyperthyroid groups (p < 0.01). WBC and polymorph counts increased in hyperthyroid but decreased in hypothyroid patients (p < 0.01). Similarly, eosinophils, monocytes, and basophils were higher in hyperthyroid patients (p < 0.01), while lymphocytes were lower (p < 0.01). Platelet counts were meaningfully reduced in hyperthyroid compared to normal (p < 0.01). These findings reflect significant hematological alterations due to thyroid dysfunction. The results established that T3 and T4 levels were maximum in patients with hyperthyroidism group and lowermost with hypothyroidism group, with TSH levels increased in hypothyroid patients’ group. Haematological aberrations were found to correlate with thyroid hormone levels: hyperthyroid individuals displayed down regulated RBC, Hb and platelets, however hypothyroid individuals presented increased MCV, MCH and platelet counts. Furthermore, disparities in immune cell parameters were detected; hyperthyroid individuals had raised WBC counts, whereas hypothyroid patients exposed with increased monocytes and eosinophils. Conclusion: These outcomes indicate that thyroid dysfunction meaningfully affects haematological profiles, with hyperthyroidism related to lower blood cell indications and hypothyroidism related with higher blood cell indications. Understanding these relationships might enable the early detection and management of blood-related problems in thyroid disorders, possibly modifying related morbidity and mortality.