Although there are common features among the anxiety disorders, they are differentiated by the focus of the child's fears. In separation anxiety disorder, children's fears center on anticipated or actual separation from their parent(s) /caregiver. Children with separation anxiety disorder are often clingy, have difficulty sleeping alone, may have school refusal, and may also exhibit or report somatic symptoms prior to or on separation. Children with generalized anxiety disorder may also express fears about harm befalling family members, but this is not the primary focus of their concern—they also experience excessive and uncontrollable worry about a number of other domains (eg, being on time, academic performance, friendships). The more worry domains that are present, the more likely is the diagnosis of generalized anxiety disorder. Children with social anxiety disorder (also known as social phobia) may present as shy and in severe cases may refuse to speak to unfamiliar people, particularly adults. They may be overly anxious about a number of social situations in which they feel awkward or uncomfortable or in which they worry about negative evaluation by others. These children may attempt to avoid situations in which social fears arise (eg, school). Panic disorder is characterized by unexpected panic attacks (not triggered by an identifiable stimulus) and typically onsets in postpubertal children and adolescents. Panic attacks typically feature a sudden onset of various somatic sensations including tachycardia, sweating, tremors, difficulty breathing, and other symptoms. Panic symptoms often result in frequent trips to their pediatrician's office, emergency department (ED), and even specialty settings such as cardiology or neurology for evaluation. Children with panic disorder may avoid, or endure with considerable distress, situations in which panic symptoms have occurred or are feared, such as the classroom, driving, or enclosed spaces; in these cases, the diagnosis of panic disorder with agoraphobia is warranted. Obsessive-compulsive disorder is characterized by obsessions and/or compulsions. Obsessions are thoughts, images, or impulses that tend to “pop up” unbidden in the child's mind and are experienced as unwanted and difficult to get rid of. Common obsessions include thoughts about contamination; doubts about completion of an activity (eg, locking the front door); aggressive or violent impulses; religious or sexual thoughts or images; a desire for symmetry; and nonsensical thoughts related to certain numbers, letters, songs, or phrases. The child will typically engage in mental or behavioral rituals, known as compulsions, in order to reduce or suppress obsessions. Common compulsions include frequent hand washing, checking, ordering, and counting. A specific phobia refers to a particular stimulus that almost invariably triggers a strong fear response; common phobias in children include fears of animals (eg, dogs, insects), blood-injection-injury (ie, “needle phobia”), darkness, and thunderstorms.