A 50-year-old woman was accompanied by the Police to our Emergency Department for acute psychosis. She had no psychiatric history. Her physical examination was normal but lab exams revealed severe hypokalemia (K = 1.7 mEq/L). She was admitted to our Emergency Medicine ward and she started ev KCl.
Further examination revealed a severe hyperthyroidism with TSH suppressed and very high levels of thyroid hormones. This case shows the importance of taking into account all causes of organic psychosis-like syndromes in order to avoid missing diagnosis.