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 dont have it; a BII-phobic, for instance, may have difficulty providing aid to someone else in an emergency situation in which blood is present.Causes of BII phobia have yet to be fully understood. There is a body of evidence which suggests the phobia has genetic underpinnings, though many phobics also cite a traumatic life event as a cause of their fear. The fainting response accompanying the phobia may have originated as an adaptive evolutionary mechanism.Applied tension (AT), a method in which individuals alternately tense and relax their muscles while being exposed to a phobic trigger, is widely recognized as an effective form of treatment for BII phobia. While AT is generally the default treatment suggestion, methods of applied relaxation (AR) and exposure-only cognitive-behavioral therapy (CBT) have been found to be effective in diminishing phobic response in some instances. Certain other strategies can be employed to temporarily alleviate symptoms associated with phobic response, such as coughing to increase cranial blood flow. The acute symptoms associated with an episode of triggering are often fully resolved within a few minutes of stimuli removal.BII phobia does bear some similarity to other phobic disorders: specifically, dental phobia (commonly considered a sub-type of BII phobia) and hemophobia. In each of these phobias, a biphasic fainting response is a common reaction to a trigger.
Signs and symptoms
In a majority of specific phobias, affected individuals experience heightened anxiety when exposed to a phobic trigger. While BII-phobics experience a similar reaction initially upon exposure, most ultimately respond to a trigger with a biphasic, or two-phase, fainting response. In the first phase, phobics often experience an anxiety reaction characterized by elevated heart rate and heightened blood pressure, as occurs in most other phobias. This is the result of increased activation of the sympathetic nervous system. However, with BII phobia, a second phase usually follows closely, in which the phobic individual experiences a massive dip in heart rate and blood pressure known as vasovagal response. Stimulation of the vagus nerve, a part of the parasympathetic nervous system, is responsible for promoting the lowered heart rate and decreased blood pressure. These physiological changes limit blood flow to the brain and can promote pre-syncope (lightheadedness, feelings of faintness) and syncope (fainting): categorized in this instance as vasovagal fainting. This second, fainting phase is not common to other phobias.A fainting response pattern is not seen in all individuals with BII phobia, but is found in a majority. Up to 80% of those with BII phobia report either syncope or pre-syncope as a symptom when exposed to a trigger.Other symptoms that may evolve when exposed to phobic triggers include extreme chest discomfort, tunnel vision, becoming pale, shock, vertigo, diaphoresis (profuse sweating), nausea, and in very rare cases asystole (cardiac arrest) and death.