This is a disorder in children in which a great deal of anxiety is expressed over the real or feared separation of a caregiver or from home. Usually when this separation occurs with a loved one, a child expresses greater anxiety than usual, and needs to know the loved one's whereabouts. Often children with this disorder prefer to remain in contact with their loved one by phone or by some other means. Furthermore, children with this disorder often worry about the safety of their loved one, imagining incidents of illness and injury. In addition, when these children are away from home, they are extremely homesick, sometimes cutting trips short. These children often have problems being alone in the house, and may follow their loved one. These children also have problems at bedtime and sleeping in their own room. They often have nightmares and try to move into their parents' bedroom. Physical symptoms, such as upset stomach and headaches, may occur as well. This disorder is fairly common in children. It develops in approximately 4% of children. Research has showed that the prognosis for this disorder is fairly good, and it does not often continue into adulthood. It also tends to arise in younger children more often than adolescents.