Background Blood pressure is influenced by biopsychosocial factors such as physical, environmental, emotional, cognitive and behavioral in hypertensive patients. ObjectiveThe aim of this study is to investigate confounding factors in hypertensive patients who have poor blood pressure control.DesignThis study was designed as a cross-sectional study.ParticipantsOur sample was 407 patients with hypertension in Rize, a Northern city in the Black Sea Region of Turkey. In study group, there were 207 hypertensive patients who had admission to emergency department due to high blood pressure. In control group, there were 200 hypertensive patients visiting family physician,who defined themselves as having regulated blood pressure over the past six months.Main MeasuresPatients completed the questionnaire including sociodemographic data, lifestyle behaviors, health risks and confounding factors via the face-to-face interview method. Key ResultsOf the hypertensive patients, 81.2% (n=168) of the study group and 34.0% (n=68) of the control group had confounding factors. There was a significant difference between the hypertensive patients of study and control group in terms of their confounding factors (p<0.001). When we asked the patients of study group questions to reveal their confounding factors, 21.3% (n=44) stated ‘anger’, 12.6% (n=26) ‘sadness’, 11.1% (n=23) ‘anxiety’, 10.6% (n=22) ‘depressed’, 9.2% (n=19) ‘unhealthy diet’, 7.2% (n=15) ‘fatigue and poor sleep quality’, and 3.9% (n=8) ‘irregular medication’. Mean systolic and diastolic blood pressure were significantly higher in hypertensive patients having confounding factors than those without confounding factors (p=0.001, p=0.001, respectively). Mean systolic blood pressure of hypertensives who stated their confounding factor as ‘anger’ was significantly higher than those the remaining groups (p<0.001).ConclusionsThis study has shown that confounding factors impair blood pressure control in patients with hypertension. Confounding factors should be kept in mind and revealed in case of poor blood pressure control in hypertensive patients.