Unfortunately, anxiety, like most mental health conditions, is not something that can be detected by a single test. Depending on the seriousness of your child's anxiety, finding a compassionate therapist who can assess and treat your child might be enough, and formal testing won't be necessary. It is wise to rule out any underlying medical conditions as a first step because certain ailments can cause symptoms that mimic anxiety. Once you are sure your child is physically healthy, a trusted physician, friends, parenting groups, and your insurance providers are all good resources for taking the next steps.