Background Atherosclerotic changes can be attributed to early endothelial damage in individuals with hypertension. We aimed to explore the relationship between endothelial dysfunction and hypertension in children, considering CIMT, FMD, and functional capillaroscopy parameters. We also analyzed the differences between dipper and non-dipper patients.Methods In this cross-sectional study, 20 patients diagnosed with essential hypertension with no target organ damage, such as retinopathy and left ventricular hypertrophy, were enrolled. The patient group comprised newly diagnosed hypertensive individuals not receiving antihypertensive treatment. All evaluations were done before starting antihypertensive therapy. Hypertensive patients were divided into two groups (dipper and non-dipper patients). As a control group, 20 age and sex-matched healthy volunteers were included. Three manual CIMT measurements were taken in each carotid artery and averaged. Basal brachial artery FMD and functional capillaroscopy density were assessed, and postprovocation measurements were obtained after in ating the sphygmomanometer cuff 40-50 mmHg above basal blood systolic pressure.ResultsAmong the patients, 11 were boys, and 9 were girls, with a median age of 16.0 (11.2-17.7) years. Signi cant differences were observed between the hypertensive patients and controls in terms of CIMT (p = 0.04), brachial artery FMD (p = 0.02), and capillary density (p <0.001). Hypertensive patients exhibited increased CIMT, reduced brachial artery FMD, and lower capillary density. However, no signi cant differences were found between the dipper and non-dipper hypertensive groups.Conclusions Understanding the vascular consequences associated with essential hypertension emphasizes the importance of early detection and management of hypertension to mitigate its adverse effects on vascular structure and function. Further research is warranted to elucidate the underlying mechanisms driving these vascular changes and explore potential therapeutic interventions to restore normal vascular physiology in hypertensive individuals.