Background: Thyroid hormone imbalance is the standard scale for its impression on numerous physiological functions, like hair growth and complete well-being of the scalp. Objective: To determine the association between thyroid hormone function and hair morphology, including its growth phases in individuals with normal thyroid function, hyperthyroidism, and hypothyroidism. Materials and Methods: A cross-sectional observational study enrolling 210 participants of Shimoga, Karnataka Tertiary Hospital, India. A total of 70 patients in each group (normal thyroid control, hyperthyroidism, and hypothyroidism) were allotted as per the sample size calculation for the study. Numerical assessments of average hair thickness, density, and hair loss were analyzed across the groups, exposing significant variations connected with thyroid status. Results: Participants with hyperthyroidism confirmed decreased hair density and increased hair loss (P < 0.01), while those with hypothyroidism displayed prominent decreases in hair thickness and irregularities in the hair growth distribution phases (P < 0.01). Histopathological observation of scalp hair samples presented morphological changes such as acanthosis (72%) and perifollicular fibrosis (64%), which were linked with thyroid dysfunction. Conclusion: This study highlights the scalp hair features and histopathological outcomes as additional indications for evaluating thyroid function. By illustrating the biological mechanisms that determine these dermatological variations, this work illustrates the significance of interdisciplinary approaches in addressing skin conditions in correlation with thyroid hormones.