Worries and anxiety during childhood and adolescence are very common. Most of the time the anxiety that kids experience falls within the normal range. However, up to 1 in 5 children may actually suffer from an anxiety disorder before they reach age 18. Anxiety is common to human experience because it is important for survival, functioning to signal the possibility of threat in the environment. Anxiety’s survival value is evident as evolution has maintained it across the animal kingdom. Because of numerous studies, we know a lot about the brain systems that detect danger and signal the alarm associated with anxiety. We believe that this important brain system, when overactive, is responsible for more severe and impairing anxiety.