Anxiety is extreme and persistent worry that interferes with daily living and symptoms can include panic attacks, physical fear reactions and attempts to avoid the situation. It is common for children to feel anxious in certain situations, but some children experience levels of anxiety that are beyond what would be expected for their age and developmental level, and this can stop them participating in school or other activities or interfere with their ability to do what other children and adolescents their age do. Nearly half of all children with a mental disorder experience an anxiety disorder.

https://www.telethonkids.org.au/our-research/research-topics/anxiety-and-depression