BACKGROUND: Cardiac tamponade is difficult to diagnose. Patients often experience sustained distress. Mood changes in the early stages of cardiac tamponade were previously described. However, precise descriptions of these moods have not been reported. OBJECTIVE: We sought to describe the mood changes specifically referred to as dysphoria in the patients' own words. METHODS: Structured and semistructured interviews were performed with 29 patients who had survived cardiac tamponade. RESULTS: Twenty-six patients (89.6%) affirmed some dysphoric mood. "A bad thing is happening" was most frequently affirmed. "Felt anxious," "could not stay still," and "difficult to settle down" followed. Answers to open-ended questions and free comments were categorized into "fear," "anxiety," "impending doom," "ill feeling," "unusual," "uncertain," "depressed," and "discouraged." CONCLUSION: The majority of patients surviving cardiac tamponade experienced a dysphoric mood. Mood changes may provide a reliable indicator for those at risk for cardiac tamponade. Cite this article: Ikematsu, Y., & Kloos, J. A. (2012, MAY/JUNE). Patients' descriptions of dysphoria associated with cardiac tamponade. Heart & Lung, 41(3), 264-270. doi:10.1016/j.hrtlng.2011.08.005.