Anxiety is a normal part of childhood. Every child goes through anxious phases that are usually temporary and harmless. But some children experience fear, nervousness, and shyness a lot more frequently and intensely. They may start to avoid places and activities, have trouble getting rid of worrying thoughts, and feel physically tense. These children may have some form of anxiety disorder. Anxiety disorders are treatable, though 80% of children who suffer from them do not get the help they need.