Diabetes mellitus (DM) is a systemic state or condition that affects several physiological and physical features of the human body that includes scalp hair morphology and hair follicles. Present study aimed to study the correlation between scalp hair features, haematological parameters and glycaemic catalogues in diabetic individuals in comparison to healthy controls. The study includes 140 participants, with 70 diabetic individuals and 70 healthy controls. Various parameters such as FBS (fasting blood sugar), PBS (postprandial blood sugar), HbA1c and haematological parameters, were assessed. Histopathological examination of scalp biopsy was done to find out the hair morphology and the anagen-to-telogen proportion, was scientifically assessed. The diabetic individuals showed significant changes in hair characteristics, such as decrease in thickness and tensile strength. Augmented hair loss and disturbed growth phase dispersal were observed, with a lesser percentage of hairs in the anagen phase (60% vs. 80%) and an increased percentage in the telogen phase (28.57% vs. 8.57%). These modifications reflect the systemic influences of diabetes such as microvascular problems, long-lasting hyperglycaemia and reduced collagen turnover. Significant associations were found among poor glycaemic control, as proved by raised levels of FBS, PBS and HbA1c and hair morphology parameters. Distinguished haematological variations, such as differences in RBC and haemoglobin levels and further inflammatory markers level were also detected in the diabetic group. © 2025 Elsevier B.V., All rights reserved.