Can I Die From Too Much Water? Blood? Oxygen?

By Brian Lemay No comments


Look at your body. It’s pretty great, right? Doing all this
complicated stuff to keep you alive? Well, your body runs by the grace of a delicate
balance, maintaining just the right levels of the materials you need to live — water,
salts, oxygen, even your own blood cells. And you already know that getting too little
of something — like water, or air, or some vitamin or nutrient — is, medically speaking,
bad. Like, leads to death. But things that are considered healthy, or
beneficial, or even essential can be just as dangerous, in the wrong amounts. In fact, many vital substances — including
some that you’re taking in RIGHT NOW! — can totally do you in, if you end up ingesting
just a little too much of them. So consider yourself warned. You know how important water is to your body. I mean, seeing how it accounts for more than
60 percent of your total body mass, you pretty much are water. And the water in your body performs a lot
of important functions. But one of the most important happens when
it combines with ions from dissolved minerals like sodium and potassium — which you probably
know as electrolytes. Your cells use different concentrations of
these electrolytes to create the positive and negative charges that regulate your internal
electrical system. This is what you use to power your moving and thinking and everything
else that your body does. Which is why dehydration is no joke. Without enough water, the loss of electrolytes
can lead to the biological version of an electrical blackout, taking power away from your vital
organs, including your brain and your heart. But what you might not realize, is that drinking
too much water can be equally dangerous. Yeah, it turns out those urban legends about
folks dying from drinking too much water aren’t legends at all, and death by water intoxication
is a thing. Fraternity hazing ceremonies and radio-station
contests that dared people to chug a bunch of water have actually ended in deaths. And so have over-zealous attempts to rehydrate
after running marathons, or hiking in hot weather, or after long, drug-fueled dance
parties. The condition is called hyponatremia, or “insufficient
salt in the blood,” and it basically means you’ve diluted your blood too much for your
electrolytes to do any good. Chug six liters of water in a sitting, and
your kidneys probably won’t be able to flush it through fast enough to re-establish a proper
balance. Instead, all that extra water starts seeking
out higher concentrations of electrolytes — especially ions like sodium — in your
cells. Which makes your cells swell up like water balloons. The lack of electrical power is a big enough
problem on its own. But some of your cells just can’t take on that much water. The neurons in your brain, for example, are
jam-packed tight into your skull, and don’t have much room to expand. That’s why the brain swelling, or cerebral
edema, caused by too much water is so dangerous. It can lead to seizures, coma, brain damage,
and death. In the end, death by dehydration and death
by water intoxication have a lot of the same symptoms, and the same mechanisms, in common.
Because they’re really the same problem — an imbalance of water and electrolytes
in the body. Another kind of substance that can easily
become too-much-of-a-good-thing? Antioxidants. You see them touted on food labels all over
the place these days, but what are antioxidants, and why should we be eating them? Well, in a nutshell, antioxidants are molecules
that can help prevent, or at least delay, certain types of cell damage, caused by oxidation. To understand how this works, we’ve gotta
first talk about the threats that they help neutralize — free radicals. Now that might sound like a ‘90s garage
band, but free radicals are potentially dangerous atoms or molecules with an extra, unpaired
electron. This unpaired electron make a free radical
lonely and unstable … so desperate to find another electron that it’ll snatch one from
anything it can. And when it does snag one from another molecule
— say, one from your cells — it oxidizes it, or causes it to lose an electron. This electron-theft can cause oxidative stress,
damaging your cells and their structures, including your DNA. Thankfully, our bodies produce antioxidants
that can help neutralize many free radicals. And we also get extra help from antioxidants
in certain foods. Fruits and vegetables naturally provide lots
of antioxidants, like beta-carotene, lutein, and vitamins A, C, and E. These compounds can give a free radical one
of their own electrons, to basically shut it up and end its destructive rampage. So they are considered beneficial, and few
if any concerns have been raised about getting too many antioxidants in your diet. But you can’t say the same for taking antioxidant
supplements. When you eat a handful of blueberries or piece
of dark chocolate, you’re ingesting a bunch of different types of antioxidants. And it
turns out that they need to work together. See, when an antioxidant gives an electron
to a free radical, it briefly becomes unstable. But when other antioxidants are around, it
can take an electron from one of them. And that electron donor, in turn, will bum one
from someone else. This free swapping of electrons works best
among different kinds of antioxidants. But, if you take a mega-dose of a single kind,
like vitamin C, you don’t have other kinds around to help re-stabilize those vitamin
C molecules after they’ve done their job. This means you can actually end up with a
lot more unstable molecules floating around your body, which is the opposite of what you
wanted in the first place. So, I’m not saying that supplements are
going to kill you or anything — although extreme oxidative stress definitely can do
permanent harm, which I’ll explain in a bit. But for now, the thing to know is that the
balance between free radicals and antioxidants is more complicated than we used to think
— and taking high doses of antioxidant supplements can just muck it up. But what about maintaining the right balance
of things you don’t ingest, or probably even think about? Like … your own blood? Blood distributes nutrients, gets rid of waste,
clots wounds, and prevents infection. It does this all using four, well-balanced
components. You’ve got red blood cells carrying oxygen
around, white blood cells to help fight infections, and platelets to help with clotting. And all
of these float around in plasma made up of water, sugar, sodium, protein, and fat. The average adult body contains about 5 liters
of blood, and we all know that you can quickly die if you lose too much of it. Maintaining the right volume of blood is important,
and we’ve talked before about how a lot of so-called “doping” in professional
sports actually involves tinkering with your blood volume. But having the right amount of blood cells
is also key to maintaining your body’s balance. And most of the imbalances that occur here
are usually caused by medical conditions. You’ve probably heard how a low blood-cell
count can be a sign of trouble, like cancer or HIV/AIDS. But more is definitely not better when it
comes to blood cells. An overproduction of white blood cells, for
example, is known as leukocytosis. And even though white blood cells are the white knights
of your immune system, this condition actually suppresses your immune response. Leukemia is perhaps the most well-known disorder
associated with excess white blood cells. It’s a blood cancer that occurs when a person’s
bone marrow starts churning out immature and abnormal white blood cells. Unlike their healthy kin, these cells can’t
actually fight infection. And they don’t die when they should — instead, they keep
dividing and multiplying, until they crowd out healthy red blood cells and platelets. Eventually, the body winds up being unable
to adequately fight infection, carry oxygen, or stop bleeding. Likewise, a mutation in bone-marrow cells
can cause the overproduction of red blood cells, like in the case of a different kind
of blood cancer, called polycythemia vera. In a healthy body, red blood cells account
for about 45 percent of the blood. But in people with conditions like polycythemia,
the blood can get too thick, increasing the risk of blood clots, heart attack, and stroke. But now, to oxygen… surely that’s something
you just can’t get too much of, right? Yeah, no. And frankly, by now you really shouldn’t
be surprised to hear it, because: balance! I think we can all agree oxygen is generally
a good thing. In fact, it’s probably the most important thing. You can go weeks without food, and days without
water if you have to, but without oxygen you could die within minutes. The air we breathe is about 21 percent oxygen.
And when you inhale, your red blood cells grab the O2 from your lungs, and pass it off
to your other cells, which use it for cellular respiration — the process of breaking down
sugar to create chemical energy. So without oxygen, your cells wouldn’t have
the energy to do anything. And yet, while they’d quickly die without
enough oxygen, they may die even faster with too much. So-called oxygen toxicity can happen when
the body is flooded with oxygen too quickly — usually in a hospital setting, like when
a person’s being resuscitated from a heart attack or stroke, or when a premature baby
is getting some help breathing. Basically, the risk here is from our old foe
oxidative stress. You know about the threat posed by free radicals,
which run around oxidizing just about anything they can snag an electron from. But nothing oxidizes like … oxygen! Oxygen itself is super needy, with two vacancies
in its outer electron shell that it would just LOVE to fill up. On its own, oxygen can go around your body
creating free radicals, which go on to steal electrons from other molecules. Of course, our bodies produce antioxidants
to repair the damage that all this oxygen can cause. But we’re used to dealing with
the stress caused by living in a 21 percent oxygen environment — not 100 percent! And in the past decade or so, scientists have
discovered that giving patients 100 percent oxygen creates hordes of free radicals that
can cause all kinds of tissue damage. In 2008, for example, researchers in Texas
found that oxygen-deprived baby mice that were treated with 100 percent oxygen experienced
brain damage, and exhibited symptoms similar to cerebral palsy. Why? Well, all that oxygen created a wave of free
radicals that caused enormous oxidative stress, doing special damage to the cells that make
myelin, the fatty insulation that covers nerve cells. But the researchers were able to treat some
of the harmful effects by giving the mice … antioxidants. Of course, only in the proper
amounts. So, the take-home message here is that your
body maintains specific balances for good reason. You live in a complex world with special,
precious amounts of what you need to survive. And you are set up to take in only what you
need, and use only what you take. So when it comes water, or oxygen, antioxidants,
or your own blood cells … you can end up having too much of a good thing. Thanks for watching this episode of SciShow,
which was brought to you by our patrons on Patreon. If you want to help support this
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