The feeling of anxiety comes from your brain. According to studies that deal with this, there are at least two areas of your brain that help to trigger the sense of fear and anxiety in your mind. It causes your brain to have a defense mechanism and then you react.
This book describes the Sighing, Diagnosis, Treatment and Related Diseases.
Sighing is considered as an involuntary respiratory inhalation which is twice as deep as the person’s average inhalation.
Sighing produces relief physically to the body as well as mentally.
The sigh helps to decrease the body Oxygen.
Treatment is to:
Provide reassurance and oxygen
Medicine to reduce anxiety or depression