Blood-injection-injury (BII) type phobia is a type of specific phobia characterized by the display of excessive, irrational fear in response to the sight of blood, injury, or injection, or in anticipation of an injection, injury, or exposure to blood. Blood-like stimuli (paint, ketchup) may also cause a reaction. This is a common phobia with an estimated 3-4% prevalence in the general population, though it has been found to occur more often in younger and less educated groups. Prevalence of fear of needles which does not meet the BII phobia criteria is higher. A proper name for BII has yet to be created.
When exposed to phobic triggers, those with the phobia often experience a two-phase response: an initial increase in heart rate and blood pressure, followed quickly by bradycardia (decreased heart rate) and hypotension (decreased blood pressure). This diminishes cerebral blood supply, and will often result in a fainting response. In an individual with BII phobia, expression of these or similar phobic symptoms in response to blood, injection, or injury typically begins before the age of ten. Many who have the phobia will take steps to actively avoid exposure to triggers. This can lead to health issues in phobic individuals as a result of avoidance of hospitals, doctors' appointments, blood tests, and vaccinations, or of necessary self-injections in those with diabetes and multiple sclerosis (MS). Due to frequent avoidance of phobic triggers, BII phobics' personal and professional lives may be limited. Some may feel that their phobia precludes them from joining a healthcare profession, or from getting pregnant. The phobia is also able to affect the health of those who don't have it; a BII-phobic, for instance, may have difficulty providing aid to someone else in an emergency situation in which blood is present.
