Apple #458: Fainting

So a couple weeks ago a friend of mine -- I'll call him Mercutio -- had to have a tooth pulled.  It was his wisdom tooth.  His dentist gave him local anesthetic, and "it didn't hurt, but the feeling and the sound of the tooth wrenching and cracking really creeped me out."

Once the tooth was out, Mercutio told them he didn't feel so well, that he felt faint, and he passed out.  When he came to, it took him a while to remember where he was and what had happened.  The technicians were wiping his face with a damp towel and telling him he was fine, even though he felt like he might pass out again.  He had to tell them to let him recline, which they did, and after about five minutes, he felt a little better and he had color in his face again.

So he wanted to know, what causes fainting and what are you supposed to do when someone says they feel faint, or after they faint?


Men faint too, you know. Even macho military dudes like General Petraeus.
(Painting sourced from the Texas Arrhythmia Institute)

• Fainting is what happens when you lose consciousness temporarily due to a loss of blood supply to the brain.

• The technical term for fainting is syncope, pronounced SIN-ka-pee.  That's a Greek term that literally means "cut off."  

• Another meaning of syncope is when letters or sounds are commonly omitted from a word, like "forecastle" is pronounced "fo'c'sle" or "ever" in poetry is often written and pronounced "e'er."  So maybe when you faint, it's like you've lost a letter or two for a while.

• Okay, but seriously, here's what happens when you faint.  In nearly every case, some stimuli or other causes your nervous system to go into a particular involuntary reflex.  The heart slow down and the blood vessels in the legs dilate.  Since the heart isn't pounding as fast, blood pressure drops, and what blood is circulating tends to hang around in the legs where the blood vessels are larger.  Thus less blood gets to the brain, and the brain temporarily shuts off -- you faint. 

• One out of every four people will faint at least once in their lifetime.

• Fainting is more common among elderly people.

• About 30% of people who have fainted once will faint again. 

CAUSES

• Even though it doesn't happen to that many people, the things that can trigger people to faint are legion.

• Common faint, a.k.a. vasovagal syncope. 

• Stress-related -- you see that you are about to be injured or you are, in fact, injured.  This is probably the type of fainting that Mercutio experienced.  Fainting at the sight of blood also falls under this category.

• Psychological -- anxiety that gets intense enough can make people hyperventilate.  This reduces the amount of oxygen getting to the brain and may trigger a faint.  

Here's an example of stress-related fainting:

It's pretty amazing that he got up right away and spelled his word correctly.  That shows extraordinary presence of mind on his part.  But you shouldn't treat this as a model for what to do.  Nobody went to help him, he should have stayed on the floor longer to give himself more time to recover, and somebody could have offered him a drink of water too.

• Environmental -- you're in a place that's hot, crowded, lots of pressure, etc.

• Physical -- standing too long with locked knees, for example.  When I was in choir back in the day, our choir director used to tell us not to lock our knees when standing on the risers, but sure enough, somebody did exactly that during a performance.  She passed out and fell right off the risers.

Fainting couches like this one used to be very common in Victorian homes.  This was because women wore corsets tied so tightly, the blood and oxygen supply to their brain was insufficient so they passed out a lot.  "Swooning" or "having a case of the vapors" gets made fun of, but probably for some women, it was a real and true thing.
(Photo by Shelley Dziedic on Photobucket)

• Other physical -- any illness that leaves you with low blood sugar or dehydrated or fatigued. Lots of conditions fall in this group, but I'll highlight some of them separately. General Petraeus said the reason he fainted was because he was dehydrated.

• Anemia -- this means you have fewer red blood cells than usual, which in turn means less oxygen gets carried around the body.  This can make you susceptible to fainting. Girls and women with heavy periods have an anemia-like situation going on, and they can be more likely to faint.

• Pregnancy -- a pregnant woman's body goes through an enormous number of changes to accommodate the fetus, and changes occur in her circulatory system too.  Those alterations can result in reduced blood flow to her brain. Or the fetus in later months may be large enough to block some major blood vessels, or the mother can get dehydrated more easily than she's used to.  All of these situations can make it more likely for her to faint.

Pregnancy can make a woman prone to fainting, or the pregnancy can also reduce her iron levels, making her anemic.  That, too, can lead to fainting.
(Photo and more information about pregnancy and fainting at Made for Mums)

• Eating disorders -- anorexia or bulimia can leave you dehydrated, with low blood sugar, or it can even cause changes in your blood pressure or circulation, any of which make you susceptible to fainting.

• Situational -- these are sort of odd reactions to particular bodily events.  They don't happen to most people, usually only those with particular diseases or conditions.

• Coughing -- people with lung disease sometimes cough so forcefully, they pass out.

• Swallowing -- people with certain diseases of the throat or esophagus may faint while swallowing.

• Urinating (micturition) -- when people empty an overfilled bladder and then pass out. Most typically when this happens, it happens to men who have gotten really drunk.

• Shaving -- people who have a very high sensitivity to their carotid area may faint while shaving, wearing a tight collar, or even turning their head.  Usually people with this sensitivity are elderly.

• After eating (postprandial) -- Some people experience a drop in blood pressure when they stand up about an hour after eating. Usually people who faint because of this are elderly.

• Standing up (postural) --  These other types of standing-up-related fainting get put into their own category.  In these cases, you feel perfectly normal while you're lying down but when you stand up, all of a sudden, you faint.  That sounds pretty common, but actually some of these types of fainting-situations are related to cardiovascular medications or certain disorders.

• Low blood volume -- this is a pretty general group which includes people who've lost blood due to some traumatic accident or other, or else they're suffering from extreme dehydration or heat exhaustion.

• Impaired circulatory reflexes -- some cardiovascular medications can interfere with the normal activity of the circulatory system and thus make you faint.  In other cases, people may have some disorder in their nervous system or they were born with some condition that makes this happen.

• Substance abuse -- this probably falls under the "impaired circulatory reflexes" category, but I think it's worth giving this one its own mention.  Illegal drugs such as cocaine or methamphetamine which overstimulate the heart can cause someone to faint.  Inhalants (huffing) can also screw up your heart rate and cause you to faint. 

• Heart disease.  Here's where the causes of fainting start to get especially serious.

• Arrhythmia -- your heart beat is erratic enough that it results in not enough blood getting to the brain.  Fainting that happens because of this can be sudden and without warning.

• Cardiac obstruction -- something in the chest is blocking the blood flow.  That "something" can be a lot of things, most of them requiring major medical attention.  It can be anything from a faulty heart valve to high blood pressure in the heart to an embolism to a heart attack.

• Heart failure -- this one seems pretty obvious.  The heart quits pumping, and blood can't get to the brain.  It's also extremely serious.

• Neurologic

• Seizures -- seizures make a person unconscious, but it's a different kind of unconsciousness than fainting.  Seizures last longer than 8 seconds and are accompanied by shaking or seizing of the arms and legs.  A person who suffers from a seizure may faint afterward.

• Strokes -- these happen when a blood vessel in the brain bursts and bleeds.  Double vision, slurred speech, loss of balance, dizziness or vertigo, and severe headaches typically accompany strokes.  Fainting may occur as a result of the brain not getting enough blood due to a stroke.

• Other -- severe migraines or also some very rare conditions involving the tongue may trigger fainting.

WHAT TO DO

• Signs you might be about to faint include light-headedness, nausea, and sometimes heart palpitations, which feel like a kind of fluttering in your chest.  Usually your face gets pale, too, because of the reduced amount of blood flow to your head.

• If you think you might be about to pass out, sit or lie down.  This helps keep the blood in the dilated blood vessels in your legs from staying there, and helps more of it get to your brain.

• Elevating the legs further helps with this.

Here's a good snapshot of what to do for someone who says they feel faint.
(Photo sourced from SodaHead)

• Tensing and flexing the muscles in your hands and arms and feet can also help stave off a faint.  Doing so helps keep the blood flowing throughout your body.

• Drink fluids, especially if you've been exercising or if you've gotten overheated.

• If someone says they feel faint, take them seriously.  Help them to sit or lie down and elevate their legs.  Do not, as Mercutio's dentist did, ignore the warning signs or tell a person that they feel fine when they are saying otherwise.

This is why you don't want to allow someone to faint away without help.  They could fall and hit something -- in this case, a burning hot stove -- and injure themselves pretty seriously.
(Drawing from Clipart ETC)

• If someone has fainted, move them so they are lying down if that is not already the case, and elevate their legs.  Again, this will help get the blood flowing back to the brain.

• After the person comes to, even if you believe the cause of fainting is not serious, do not allow them to get up again for a good 15 to 20 minutes.  This is to make sure the blood pressure has restored itself to normal levels and the brain is getting enough blood.

• Give them water or some other beneficial fluid to drink, if it's available.

• If the person does not come out of the faint relatively quickly, yelling or briskly tapping their arm or leg may help them come to.  If the person still does not respond after about a minute, call 911 immediately.

• Once medical professionals are on the scene, they will do what they can to restore blood pressure and treat any other symptoms.

• If you have fainted, in most cases, you won't need to see a doctor to find out if anything serious is going on that needs attention.  However, if you've experienced the following symptoms along with the fainting, then it's a good idea to go see a doctor:

• Irregular heart beat
• Chest pain
• Shortness of breath
• No warning signs preceding the faint
• Blurred vision
• Confusion
• Trouble talking afterwards
• Taking longer than a few seconds to regain consciousness
• Fainting when you turn your head to the side
• Fainting more often than once a month
• If you have been diagnosed with diabetes, high blood pressure, or heart disease
• If you're pregnant

WHY FAINTING HAPPENS

• The more I've read about this, the more I started to wonder, why do our bodies do this anyway?  If it's an involuntary reflex that kicks in, there must be a reason why our bodies come equipped with this response.  So why does it happen and what good does it do us?

• One site calls fainting an "energy conserving mode."  The fainting system actually hopes that the faint will knock us flat to the floor and require us to cease all activity.  The faint, in effect, puts a stop to whatever the stimulus was that triggered the faint, or gets us away from the unpleasant thing even momentarily, and by throwing us to the floor, it puts the brain at the same level as the feet, allowing the blood to flow back to the brain and the blood pressure to re-regulate itself.

• This in no way suggests that if you feel a faint coming on it is somehow healthier or better to allow yourself to go ahead and faint.  If you take the steps necessary to avert the faint, you will be making conscious choices to interrupt the negative stimulus and to restore blood flow and blood pressure to levels that your body likes.  And you'll be doing so in a way that won't put yourself at risk for cracking your head open.

• Another reason we faint is, I suspect, related to the fact that we walk upright.  It's a really tough thing our circulatory systems do, pumping blood upward, against the pull of gravity, to the most crucial and oxygen-hungry part of our bodies, the brain.  That's such a challenging feat, no wonder it goes a bit haywire now and then.

• I'm thinking about this because of the entry I just did about bats.  They can hang upside down for hours -- they sleep that way -- and not be bothered by blood rushing to their heads or taking off suddenly and flipping themselves upright again immediately.  If we tried hanging upside down for hours and then suddenly flipping ourselves upright, I bet we'd pass out.  But bats don't have any trouble with that because their bodies are a lot smaller and their circulatory systems don't have to work as hard to keep everything oxygenated.

Speaking of animals and fainting, these are called "fainting goats" but really what afflicts them is not a faint.  They fall down not because of reduced blood volume to the brain but because of a stiffening in their legs.  


Sources
emedicinehealth, Fainting
onelook.com, syncope
NIH, Medline Plus, Fainting
Nemours, TeensHealth, Fainting
Texas Arrhythmia Institute, Syncope (Fainting)
Cleveland Clinic, Syncope Care & Treatment
WebMD, Fainting Treatment
Family Doctor.org, Fainting
ClevelandWomen.com, Fainting