Introduction and research objectives: The study, which was conducted at the Unified Emergency Department of Zadar General Hospital, focused on hypertension, a condition that affects millions of people worldwide and causes a significant number of cardiovascular problems. Hypertension often shows no symptoms and is usually only discovered when complications arise. The aim of this study was to use the ICD-10 classification (I10-I15) to analyze how demographic factors such as age and gender influence the incidence and treatment methods of hypertension in 2022 and 2023. Materials and methods:The study included patients admitted to the Unified Emergency Department of Zadar General Hospital in 2022 and 2023. Retrospective data from the hospital information system were used, including demographic information (age and gender) and diagnoses of hypertension according to the ICD-10 classification (I10-I15). The analysis included statistical processing of variables such as the prevalence of hypertension between genders and age groups and differences in treatment methods. Ethical aspects of the study included ethics committee approval, anonymization of data and restricted access to protect patient privacy. Results:The study, which was conducted in 2022 and 2023 in the Unified Emergency Department of the Zadar General Hospital, showed a high prevalence of essential hypertension (I10), which was present in 99.13% of the 2,183 patients. Most patients were treated as outpatients (95.19%), with no significant gender differences in the prevalence of hypertensive heart disease. Due to the lack of data, some hypotheses could not be tested, indicating the need for more comprehensive research. Conclusion: The research findings highlight the need for additional analysis to better understand the dynamics of hypertension treatment, particularly in older age groups where essential hypertension is most prevalent. Secondary hypertension is rare, which also points to the need for expanded studies to optimise therapeutic approaches.