People with anxiety disorders respond to certain objects or situations with excessive fear and often unexplainable dread. Anxious reaction manifests as thoughts, feelings and physical reactions to those objects. What often brings people to seek professional help is the intolerable and uncontrollable physical symptoms, such as a rapid heartbeat, shortness of breath, tunnel vision, and sweating. Anxiety disorders come in different varieties and intensity, such as social anxiety, obsessive-compulsive disorder, panic disorder, phobias and post-traumatic stress disorder (PTSD).