BackgroundLack of adherence to treatment in patients with arterial hypertension leads to poor blood pressure control, increased morbidity and mortality, and increased costs to health and social care. Regular assessment of treatment adherence as well as factors influencing it is important to improve patient adherence and consequently increase treatment efficacy. Personal beliefs, particularly illness representations, are significant factors that influence adherence.ObjectiveThe aim of this study was to assess the associations between adherence to treatment, illness perception, and selected sociodemographic and clinical characteristics in patients with arterial hypertension.MethodsIn this cross-sectional observational study, 235 patients with arterial hypertension completed the Hill-Bone Compliance to High Blood Pressure Therapy Scale and the Brief Illness Perception Questionnaire. Associations between variables were assessed by Spearman ρ and multiple linear regression analysis.ResultsYounger age, male gender, overall number of drugs used, and poorer beliefs related to the timeline, treatment control, and understanding were associated with higher levels of nonadherence. The final regression model significantly (P ≤ .05) explained 19.4% of the variance in diet adherence, 5.0% in appointment keeping, and 17.8% in medication adherence.ConclusionComprehensive care aimed at regular evaluation of illness perceptions with an emphasis on increasing understanding of the disease and its treatment and reducing patient worries and negative emotions seems to be a relevant strategy for improving adherence to antihypertensive treatment in everyday clinical practice.