Hyperventilation syndrome may occur when a person breathes from the chest, which can lead to overbreathing (exhaling excessive carbon dioxide in relation to the amount of oxygen in one's bloodstream). Hyperventilation syndrome can cause respiratory alkalosis and hypocapnia. This syndrome often involves prominent mouth breathing as well. This causes a cluster of symptoms, including rapid heart beat, dizziness, and lightheadedness, which can trigger panic attacks.
A person with panic disorder experiences sudden and repeated panic attacks—episodes of intense fear and discomfort that reach a peak within a few minutes—during which time the individual experiences physical symptoms such as chest pain, heart palpitations, breathlessness, vertigo, or abdominal distress, sometimes accompanied by the fear of dying or of going insane. These symptoms may seem similar to those of a heart attack or other life-threatening medical conditions. Panic disorder is often diagnosed after medical tests or emergency room visits have ruled out other serious illnesses.
Social anxiety disorder (previously called social phobia): People with social anxiety disorder have a general intense fear of, or anxiety toward, social or performance situations. They worry that actions or behaviors associated with their anxiety will be negatively evaluated by others, leading them to feel embarrassed. This worry often causes people with social anxiety to avoid social situations. Social anxiety disorder can manifest in a range of situations, such as within the workplace or the school environment.