Health psychology/Phobias & anxiety · Anxiety / phobia

Blood-injection-injury phobia

What it means

A specific phobia subtype unique in its physiology: a biphasic vasovagal response (transient tachycardia then bradycardia/hypotension) causing fainting — unlike other phobias where arousal is sustained.

Worked example

Fainting at the sight of a needle or blood.

In the exam

A young man reliably faints whenever he sees blood or has a venepuncture, with a brief rise then sharp fall in heart rate and BP beforehand.

What settles it

Blood-injection-injury phobia is the only phobia that classically causes a VASOVAGAL FAINT (parasympathetic overshoot). Other specific phobias produce sustained sympathetic arousal, not syncope.

Classically confused with

Specific phobia

Source: DSM-5