The term obsession, in common parlance, means a thought that comes to mind with a certain insistence. Although it is normal that in certain conditions, marked by real difficulties, thinking back with a certain insistence on the particular problem that torments us, obsessions are different from normal concerns for their content and devoid of factual basis for the frequent recurrence. The differences between normal intrusive thoughts and obsessions are pathological, mainly quantitative and recursive. The pathological obsession, in fact, have a higher rate and produce more intense emotional reactions and end up becoming a source of painful discomfort that interfere heavily on the performance of normal relational activities of daily living.