Anxiety is the term used to describe a group of mental illnesses, characterized by a permanent sensation of fear and terror. The sufferer may feel threatened by various persons, objects or situations, but the fear is exaggerated and illogical. Phobias, stress disorders, obsessive-compulsive actions are all symptoms of anxiety. This disease affects children and adults as well and its mechanisms aren’t totally known, although scientists think stress overload is the main trigger for anxiety.