Blood and injury phobia: Cause or consequence of fainting?

Blood/injury phobia is a problem encountered commonly in clinical practice and is accompanied by syncope in about 80% of the cases. A vasovagal reaction to the sight of blood is not a specific feature of the blood phobic population per se and has been widely described in blood donors and in normal subjects viewing violent or surgical films. It may be that a dysfunctional constitutional autonomic substrate predisposes some individuals to marked vasovagal reactions. Indeed, in comparing the hemodynamic response to head-up tilt in blood phobic and normal subjects, nine of eleven blood phobic subjects experienced syncopal or presyncopal events. Thus, subjects with blood/injury phobia are susceptible to vasovagal syncope, even in the absence of blood or injury stimulus.