Fear of fainting or collapsing is common during panic. Dizziness or feeling faint occurred in 83 percent of panic patients surveyed in one study.
People rarely faint during anxiety attacks.
Feeling faint stems from hypertension or overbreathing. Some people who feel faint while anxious are unaware that they are hyperventilating. Close observation, however, often reveals that they are overbreathing.
Anxiety and fear cause faster breathing both in people with and without Anxiety Disorders. Hyperventilation often begins as a reaction to a feeling that the person cannot catch his or her breath. The changes caused by hyperventilation further frighten the person, and a vicious cycle of overbreathing and greater fear ensues. Nearly all of the symptoms associated with panic can be caused by hyperventilation.
Although hyperventilation causes a feeling of anxiety dizziness and some claim actual fainting as well, we have never seen a person faint while hyperventilating. In contrast, most blood-injury phobics have fainted repeatedly at the sight of blood or injury. Rarely, hyperventilating people feel so faint that they lie down, shut their eyes, and stop talking, but they still remain aware of what is happening to and around them rather than passing out altogether.
Learning to control hyperventilation helps some people with anxiety.