Anxiety disorders constitute a mental aberration that debilitates the social life of the patient, who suffers from attacks of irrational fears. His anxiety presents itself in many forms, can have a multitude of causes and can be evoked by many triggers. This article deals with, successively: panic disorder, generalized anxiety disorder, phobic disorders, (posttraumatic) stress disorders, and obsessive-compulsive disorder. More than one out of ten adults are living with some kind of anxiety disorder. For treatment, both psychotherapy and drugs are relevant.