Anxiety is not just feeling worried, nor is it always disordered. We all deal with a normal amount of anxiety and stress. People with anxiety disorders respond to certain objects or situations with fear and dread. They have physical reactions to those objects, such as a rapid heartbeat and sweating. An anxiety disorder is diagnosed if a person:
Has an inappropriate response to a situation
Cannot control the response
Has an altered way of life due to the anxiety
National Institute of Mental Health
https://www.nimh.nih.gov/index.shtml
Mental Health
Pathway 2 Success
https://www.thepathway2success.com/helping-kids-with-feelings-of-anxiety-worry/
Freeing Your Child from Anxiety: Powerful, Practical Solutions to Overcome Your Child's Fears, Worries, and Phobias
by Tamar E. Chansky
Helping Your Anxious Child: A Step-by-Step Guide for Parents
by Ronald M. Rapee
Fighting Invisible Tigers: Stress Management for Teens (Revised & Updated Third Edition)
by Earl Hipp