A bulk of studies showed an association between stressful events and juvenile idiopathic arthritis (JIA) but failed to identify specific psychological tendencies that contribute to the patients' vulnerability to stress. The purpose of this paper is to identify psychological tendencies specific to JIA that would unravel characteristic sources of stress. The study is based on the cognitive orientation model of health, which enables us to identify these kinds of tendencies in terms of four belief types (beliefs about self, general beliefs, beliefs about norms, and goals) that refer to specific themes. This is a case‐control‐cohort study that included a sample of 36 patients (mean age = 12.44 years,
SD
= 2.97, 21 females) and 41 matched controls (mean age = 13.15 years,
SD
= 2.01, 22 females). The JIA cognitive‐orientation questionnaire was administered, and relevant medical parameters were recorded. The belief types differentiated between the two groups, and the patients were characterized using six themes. Examples of the themes are being over‐sensitive, striving for success, and not fulfilling duties well. The themes differentiated between the participants' groups with an accuracy of 89.1%. The likelihood of the patients being characterized by the themes is 3.24–9.35 times more than the controls. The psychological tendencies of JIA were discussed as generators of stress (e.g., being over‐sensitive) and cognitive conflicts (e.g., the contradiction between striving for success versus not fulfilling duties well). Also, the suggested reflections of these tendencies in the health workers' and patients' relationships, such as egalitarian interaction, and non‐formal communication style, were described.