Blood-Injection-Injury Phobia: More Than You Wanted To Know

Even if you’ve never heard of the diagnostic label, Blood-Injection-Injury Phobia (let’s call it BII for brevity’s sake,) chances are you’re still familiar with the condition.  It is relatively rare but still considered common by mental illness standards, occurring in approximately 3.5% of the population by most estimates, and it is characterized by an intense overreaction to seeing blood, injections, injuries, or even to the anticipation or imagining of blood, injections, or injuries.  This intense overreaction could involve anything from feelings of intense fear or disgust, increase heart rate, a drop in blood pressure, or fainting.  

This profile of symptoms is different from other phobias, and some have even argued that BII is not a true phobia in the classic sense. Classically, a phobia is an intense, irrational fear of something like airplanes, dogs, closed spaces, spiders; a person could develop a phobia to just about anything.  Physiologically, when a person experiences a phobia, there is an extreme activation of the sympathetic nervous system—that’s the branch of the nervous system involved in many different automatic reflexes designed to help you in times of danger, which is why it is commonly known as the “flight or flight” system.  Actually, it’s more complicated than that, the sympathetic nervous system kicks in for other reasons as well, but let’s keep it simple for now.   When the evolutionarily primitive sympathetic nervous system, regulated by the spine and brain stem, is dialed on “low,” it mainly just assists in keeping you alert and awake.  When it gets kicked up to “high,” like when you encounter something terrifying or surprising, you’ll notice a variety of physical changes like increase heart rate, increased respiration, muscle tension, sweatiness, feeling hot or cold, pupil dilation, blood vessel constriction, and slowing of the digestive system, just to name a few.  That’s what most people experience when they have a phobia.  But in the case of BII, it doesn’t work the same way.

When a person with BII experiences an onset of symptoms, the reaction is not merely an activation of the sympathetic nervous system, and subjective feelings of fear may not even be present, unlike with a classic phobia.  I can speak from personal experience as I have this condition; when I was very young, maybe 2nd or 3rd grade, my teacher showed the class a photo of a finger with a blackened fingernail from bruising (don’t ask me why), and the result was that within a few seconds I fell over from my chair to the concrete floor, unconscious.  It had never happened before.  I recall a mild feeling of disgust at the picture before passing out (“ewww that’s gross!” is what my friends told me I said right as I fainted), but I definitely did not feel afraid of the picture.  Throughout my life when I have encountered similar situations that made me feel woozy or even pass out, I have never felt intense fear as with a fear of snakes, for example.  I also do not have any classic phobias, no irrational fears, though research suggests people with BII are at higher risk for other phobias.  

Another way in which BII can differ from a classic phobia is that though there may be an initial activation of the sympathetic nervous system, causing a person’s heart rate to go up and other signs of sympathetic activation, what quickly follows is a rapid and dramatic activation of the parasympathetic nervous system.  Normally, when the parasympathetic nervous system is dialed to “low,” it supports physiological changes that are associated with calmness and relaxation.  When the parasympathetic system is dialed to “high,” as in the case of BII, the result can be that the person becomes dizzy, weak, or even lose consciousness.  The body goes into shock, just as if the person actually experienced a serious injury.  The normal purpose of this response is likely that it is protective to lower one’s blood pressure if one is wounded, because that should reduce bleeding and speed clotting.  And it is considered normal for people to experience a mild degree of discomfort or dizziness at the sight of blood.  But for people with BII, the primitive brain seems to make the mistake of interpreting the sight or anticipation of injury as an actual injury to the body, and then grossly overreacts.  In other words, BII seems to start as an extreme example of what happens normally to people, but then becomes a “phobia” because people become afraid of situations where they think they may lose consciousness.  

There appears to be two mechanisms at work with BII: a psychological and a physiological mechanism.  The physiological mechanism likely relates to a hypersensitive vagus nerve and/or other parts of the autonomic nervous system.  The vagus nerve is one of the 12 cranial nerves located along the brainstem.  It is responsible, in part, for regulating the parasympathetic nervous system. Stimulation of the nerve causes an increase in parasympathetic activity, such as a reduction in heart rate and blood pressure.  An interesting study made a case that most people with BII have an inherent difficulty regulating vasovagal activity that predisposes them to excessive drops in blood pressure in various situations, not just in relation to blood or injections, and so this predisposition just becomes very obvious around blood.  This would also help explain why BII is strongly heritable.

But there is also likely a psychological component to many circumstances where a person with BII experiences dizziness or fainting.  Certainly there is a psychological component in how a physiological predisposition to blood pressure dysregulation becomes a phobia: some people become frightened of situations where they might faint, and can then become highly avoidant of such situations or feel extreme levels of distress or fear in them.  But sometimes an episode of fainting is triggered by a psychological response to a stimulus, not by a primitive, reflexive vasovagal response.  You can listen to a very interesting example of this from the Radiolab podcast episode entitled “The Heartbeat”.  The original story was broadcast to a live audience, which is significant because the immediacy of the story likely contributed to the audience’s reaction. In the story, a woman describes how after heart surgery her heart pumped much louder than it ever had before.  So loud, in fact, that it was apparently audible from a couple of feet away!  The producers found various ways of demonstrating this in the show, including by using very loud sound effects of heartbeats in the theater, so that the audience could viscerally understand how loud, distracting, and even upsetting this poor woman’s heartbeat became after her surgery.  The podcast hosts explain that after the show, they were shocked to learn that several members of the audience experienced extreme reactions to the performance, including fainting and vomiting.  Why would people experience such reactions?  When most people think of BII, they typically expect a person to faint in response to the sight of blood, not the sound of a heartbeat.  In reality, whether the stimulus is visual or auditory is less important than how the person feels about it.  In this case, the audience members who were most affected may already have had BII and its accompanying, hypersensitive nervous system, but on top of that they were likely affected psychologically by aspects of the performance that increased their sense of empathy for the woman.  Empathy, or the ability to imagine how someone else feels and to even feel what they are feeling, is an invaluable tool that promotes the ability of humans to be social, helpful creatures, but in the case of BII it can actually be a problem.  The effectiveness of the storytelling, combined with the loud, inescapable sounds of a heartbeat pumping through the theater, combined with the message that the woman in the story found these sounds to be very distressing, were all intended by the producers to help the audience feel empathy for the woman; to feel what she felt.  This is what good storytelling is all about, of course, but because the subject related to the heart and blood, some people in the audience with BII likely felt empathy for the woman and this caused their brain to respond as though it was really happening to them. Consequently, this triggered in some people an activation of the sympathetic system followed in some cases by an excessive activation of the parasympathetic system.  Some people apparently threw up, other people passed out, not because they were necessarily afraid of what they were experiencing, but because they could so effectively empathize with it.  

The role of empathy in BII is what I personally find most fascinating in this disorder.  The brain is a complex series of feedback loops between different areas responsible for different functions.  Different parts of the brain “listen” to what other parts of saying, and respond accordingly. In the case of BII, more primitive parts of the brain seem to be listening to higher-level emotional areas associated with empathy and responding to these feelings no differently than if the person was actually injured or seeing blood.  

Some people may truly experience fear at the sight of blood, or needles, no different than if they saw a vicious dog or a cobra.  But for others, like myself, the problem relates more to our capacity for empathy.  Let me give another example from my own life: one day I was driving down the highway and listening to a radio show on the topic of stress, and a story was being told by a man who had fallen out of a motorboat and had his leg severed by the boat motor.  He was describing in detail how he felt and what he was thinking about as this happened to him.  In my own mind, not consciously, I was imagining the scene in my head and projecting myself into the place of the storyteller, and I noticed to my surprise and disappointment that I was starting to feel dizzy.  Recognizing what was happening to me, I turned off the radio, but it was too late: probably what happened next was that I continued to focus on my own feelings of dizziness, which likely increased the intensity of the parasympathetic response.  I pulled off the side of the road and stopped the car, but by that point my blood pressure was so low that my brain was not able to function well (neurons need oxygen from blood to function), and so, with my head in my lap I actually took my foot off the brake and thought I would take the car back onto the highway! This would have certainly resulted in a terrible car accident that I might not have survived, if it wasn’t for the fact that I could not steer with my head in my lap and while only semi-conscious, and wound up crashing my car into some trees at the bottom of an embankment. I wasn’t hurt, fortunately, but I tell this story now because it shows how serious a problem BII can be.  I was nearly killed.  I had never in my life experienced a similar episode of fainting while listening to something, and only a handful of times in my life had it ever happened at all.  I learned to be more mindful about what I listen to while I’m driving, but there are more lessons to be learned from my experience.  I will also try to share with you what I have learned over the years that has helped me to cope with my problem.  

First, it is important not to minimize the dangerousness of BII. Many health professionals know that some of their patients get woozy or faint when they receive an injection or get blood drawn, but they don’t often think to ask about in how many other kinds of situations this occurs.  They should ask, because the patient may not recognize they have BII.  A person with BII needs to be aware of what kinds of situations may trigger an episode of dizziness or fainting, because as in the story I just told if a person faints at the wrong time, the results can be deadly.

Next, once a person knows they have BII, they need help learning how to prevent losing consciousness, which is the most severe and dangerous symptom of the disorder.  Here are some tips:

  1. Stay rested, fed, and hydrated.  I have learned from experience that I am more susceptible to drops in blood pressure if I am tired or dehydrated.
  2. Get your blood pressure back up!  This is key! If possible, lay down on your back and raise your legs up just above the level of your heart (or higher), which will use gravity to increase the blood pressure in your head.  I find this extremely effective.  If, however, you cannot lay down, then try to raise your blood pressure by tensing up all the muscles in your body.  Phlebotomists (the nice people who take your blood at the physician’s office) don’t like this advice because they want you to relax—if you are too tense then your arteries constrict and it becomes harder for them to inject the needle.  But relaxing is the worst thing to do when your blood pressure drops.  So when getting blood drawn, laying down is your best option. Otherwise, do your best to get your head below the level of your heart and tense all your muscles as hard as you can.  Another option might be, if practical, to quickly try to exercise, for example run as fast as you can or do jumping jacks to boost your heart rate.  But be careful, if you feel yourself fainting then stop and lay down, you don’t want to pass out while running and hit the concrete at high speed!  Another potential preventive treatment, though I haven’t seen any research on this, could be to take medications that raise blood pressure prior to situations that are triggering.   
  3. Distract yourself.  Remember how empathy is related to BII: if you focus on yourself being injured (like watching a needle being injected into your arm) or feel strong empathy for someone else’s injury, you are more likely to have an episode.  So try to think about something else, strike up a conversation with another person, and get your brain to stop focusing on the topic of blood or injury. 
  4. Condition yourself.  When the popular TV show “ER” was on, I used to deliberately watch the parts with graphic images of injuries as a way of training my brain not to overreact at the sight of realistically portrayed gore.  This kind of treatment is technically called “graduated exposure.”  Now, that kind of conditioning won’t likely generalize to other situations: I learned to watch “ER” without worrying I might pass out, but I still have trouble getting blood drawn.  To address that, I would likely need to spend concerted time working with a phlebotomist, gradually exposing myself to needles and injections repeatedly while also practicing keeping my blood pressure up, and hopefully over time I would train my brain to not associate needles with fainting.  I haven’t yet committed the time to this project, but in theory it should work.   
  5. Watch your thoughts.  Whether you are empathizing with a person who is injured or you are terrified at the sight of blood, BII isn’t just about reflexes you have no control over, your thoughts are playing a role and contributing to the symptoms.  You may not control your cranial nerves, but you can control your thoughts.  Certain thoughts can contribute to the problem, like “this is awful!” and certain thoughts can help prevent a problem, like “I can handle this.”

Over the years I have found myself less and less susceptible to fainting, probably as a result of exposing myself to provocative situations and gradually conditioning my brain not to overreact.  But there may be limits to what I, or anyone else, can achieve. Because the likely root cause of BII relates to the autonomic nervous system, there may be a limit to how much we can “tweak” through behavioral interventions.  Maybe in the future we will have more sophisticated treatment options.

Another reason to suspect that BII cannot be “cured,” is that episodes of dizziness, fainting, vomiting, or severe distress related to blood and injury seem to be able to happen to anybody at any time.  While people with BII may experience a lifelong pattern of predictable episodes, other people may never have an episode until an unusual or surprising circumstance occurs.  For example, even though surgeons are generally comfortable seeing blood and injuries, anecdotally there is evidence that many have experienced occasions when they became physically ill or even fainted, and what seems to make the difference is if what they experienced was surprising, dramatic, and unexpected.  In other words, being able to anticipate blood and injury may prevent an excessive vasovagal response in most people.  Why would this be?  Anticipation may give us the time we need to suppress or inhibit our reflexive autonomic response to a frightening situation; to help calm ourselves down before we freak out.

So while there are many things you can do to help prevent fainting episodes, or syncope, to use the medical term, there many not be any way to guarantee 100% success.  But if you are like me and you live with BII, hopefully you’ll find something in this post useful for you in preventing future problems.  Remember, if you want to get really serious about exploring treatment options, including more advanced techniques like graduated exposure, or if you’re having trouble getting a handle on panicky reactions to situations, you may want to consult a psychologist to increase your chances for success.  Though research in this area is limited, the best treatment currently seems to be cognitive-behavioral therapy and graduated exposure.