According to the WHO, an estimated 8 million people currently suffer from cancer. The number of rheumatism, arthritis and other disease sufferers is unquantifiable. Every day, 300 million people world-wide undergo operations. However, the perception of pain depends on the individual’s state of consciousness and on the so-called pain threshold which is a measure of the individual’s intensity of pain perception. In short, pain is a natural warning sign. In her series entitled „Mysteries of Health”, the author talks about the history and principles of anaesthetics in its broad understanding.