What are some specific signs/symptoms people might confuse for
anxiety but are not symptoms of a disorder?

These can be anything from normal feelings of worry, to signs of other mental health conditions that may be confused for anxiety symptoms.

Anxiety is an emotional and biological condition that is mimicked by other symptoms such as ADHD, irritability, anger, moodiness, depression, and generalized worry.

ADHD

ADHD or attention deficit hyperactivity disorder presents with disorganization, impulsivity, overactivity, sometimes chattiness, inattention, and/or inability to settle down to do a task for more than a few minutes. The person may appear flustered and irritable mimicking anxiety, but actually have this different condition that needs to be managed differently than anxiety.

Irritability

Irritability, anger and moodiness can be concealed by a seemingly anxious state when the person doesn’t want to reveal their fury. Instead they appear unstable and even flighty when they attempt to hide their true feelings. They feel disturbed or guilty for feeling angry and try to cover it up unsuccessfully acting as if they were anxious. Folks who are afraid of expressing anger and unconsciously or consciously conceal it.

Depression

Depression is a deep-seated emotion that is often concealed even from the person who feels this way by irritability and instability. The person feels very down in the dumps, may find they aren’t eating or sleeping well and their self-esteem is low, but they can’t put their finger on what is happening to them. They assume wrongly they are just anxious. Anxiety and depression often go together, however, so both may be present. Moodiness may also be a symptom of depression that comes across as irritability and anxiety.

Generalized Worry

Generalized worry about something one anticipates may be reasonable caution that is experienced as anxiety. When the situation passes or resolves, then the person feels calm again. If this is short lived it can be ascribed to worry rather than an anxious state.