Blood-injection-injury type phobias

According to the DSM-IV classification of mental disorders blood-injection-injury type phobias constitute a subtype of specific phobias. It includes fear of blood (hemophobia), injury phobia and fear of receiving an injection (trypanophobia and some other names) or other invasive medical procedures.

A distinctive feature of phobias of this type is their vasovagal manifestation. For most fears (both normal and abnormal) the response to the feared stimulus includes the accelerated heart rate. In the cases of blood-injection-injury phobias a two-phase vasovagal response is observed: first a brief acceleration of heart rate, then its deceleration, bradycardia, and dropped blood pressure. the above may also lead to vasovagal syncope (fainting).

These characteristic vasovagal reactions may contribute to the development of a phobia, but not necessarily: the occurrence of vasovagal reactions (as reported in 1994) is 5-15%, while for the phobia it is 3-6%.

The other factors contributing to the development of the blood-injection-injury phobias are the same as for other specific phobias.