[It is more difficult to smash a prejudice than an atom].

The death of a 17-year-old patient caused by hypokalemia-induced arrhythmia illustrates the tragic dangers of the current paranoid preoccupation, particularly of young women, with physical beauty and low body weight. This case also reminds the reader that modern textbooks are not always sufficiently reliable. An intellectual approach how to circumvent diagnostic misinterpretation even in the context of misleading textbook information is proposed.