Panic Disorder is characterized by the sudden and unexpected onset of physical sensations that are mistaken to be signs of illness, fainting, heart attack, insanity, or even impending death. A diagnosis of panic disorder will come only after other medical or psychiatric conditions are ruled out as causing the symptoms. There are also instances where a child begins to avoid certain situations or locations because of fear that it will provoke a panic attack. In those cases, the child is diagnosed as having panic disorder with agoraphobia. Agoraphobia typically involves fear of being in situations where it may be difficult to escape - like being in a crowd, standing in a line, being in open/enclosed spaces, or traveling in a bus, train, or a car. For these children, their world may begin to get progressively smaller as they are only comfortable staying in a "safe" environment. They also experience distress because of the uncomfortable sensations that they don't know how to manage.