Highly sensitive people perceive their environment on all levels and with all senses. This enables highly intensive experiences. The range of possible manifestations of high sensitivity is very wide. Practically every sensory impression can be perceived more strongly and thus in greater detail. Often this characteristic is mistaken for mere nervousness and sensitivity. The increased reception of stimuli and their deeper processing result in character traits such as introversion and intense experience of interpersonal relationships. Strong reactions to medications, alcohol, and caffeine may also occur, as well as susceptibility to stress, pressure to perform, and time constraints. Currently, no accepted scientific theory exists. A hereditary predisposition is cited as likely. The idea that it is a “mental disorder” or “disease” is rejected. According to one explanation, the thalamus, a part of the diencephalon, classifies more stimuli as “important” in highly sensitive persons, which then reach consciousness.