I think we can all agree water is pretty cool for a lot of reasons.
Not the least of which is the fact that were it not for water,
I wouldn’t be here telling you this and neither would you be in a position to listen.
And pretty much any form of life would not exist.
Water might be the best example of the word ubiquitous.
We get advice from everywhere that we should always drink water and stay hydrated
2 litres or 8 glasses of water a day, even on a normal day,
to keep our body in a healthy state.
But as with most things, too much water in a short span of time can be harmful.
Why might you reasonably ask?
Well, before we get to that, let’s understand a few important facts about water.
First of all, as you might know, about 70% percent of our body is water.
It is literally everywhere;
from a place as intuitive as your vessels to the smallest cells and their organelles
to the tiny spaces between them.
And as with everything about your body, this water is not static, it is in constant flow.
As you intake water throughout the day you also lose it
along with impurities and metabolites that your body can do without.
In every moment of your existence you are losing water through either sweat,
urination, defecation, exhaled breath, and in other ways.
But what does the water do in the most ginormous,
freaky rollercoaster that is your body?
Well, it mostly spreads throughout the body but not in a random or chaotic fashion.
It follows the process of osmosis.
The process of osmosis dictates that water, which is a solvent in this scenario,
will move across a membrane from areas with low solute concentrations to high solute concentrations
with no other intervention or expenditure of energy.
The most important solutes in your body are known as electrolytes
and the most relevant among the electrolytes is sodium.
Now that might sound quite complex but if we grossly oversimplify,
we can say that our buddy water has the biggest crush ever on the new girl in school called sodium
and he more or less follows her around everywhere she goes.
Now, with the chemistry lesson out of the way let us return to the question at hand.
What happens if you drink too much water?
Well, your body tries to compensate by eliminating the excess however it can,
with the most powerful way of doing so being through the kidneys.
But since the excretion capacity of a healthy kidney caps at about 1 liter of water per hour,
going beyond that capacity can have harmful consequences.
So, what happens if you drink enough water to make the kidneys work overtime?
Well in order to understand just how screwed you might be,
we need to mention a few things about sodium.
2/3 of the total sodium in the body is located outside of your cells at any given time,
which is not a problem as water goes where sodium goes,
where we have high solute concentrations.
However, since we’re talking about consuming too much water,
the extracellular space is no longer the area with the highest solute concentration
because it is diluted.
Therefore, the excess water rushes across the membranes inside the cells of your body.
This leads to swelling of the cells,
which in most cases is not such a big deal because the cells are designed to resist changes in their volume.
And can expand and shrink without permanent damage to the body,
given they have space to maneuver.
But here lies the issue -
because unlike with soft tissue like fat and muscle,
some organs do not have much space to maneuver,
and the one that has the least also happens to be your most important organ-- the brain.
Given that it is almost completely encased within the cranium,
the cells that make up your brain can’t handle big changes in volume,
because they simply don’t have the room to do so.
The cells in the brain have very little to no leeway when it comes to volume variation.
An increase in cellular volume can very quickly lead to a build up in intracranial pressure.
And pressure that builds up in a closed space only wants to escape -
somewhat like a shaken soda can.
This pressure can cause compression on the vessels providing nutrients to your brain
and can even push important brain structures such as the brainstem outside the cranium
in what is called brain herniation.
Which can cause very serious damage and lead to headaches,
confusion, seizures, lethargy, drowsiness, coma and even death!
Now, the thought of your brain exploding and that too from an overdose of water
might sound quite scary,
but before you throw that glass in the sink,
it might comfort you to know that cases of water intoxication are rare
and occur in special situations such as professional long distance runners,
abnormal levels of ADH (hormone that regulates a ton of stuff such as water retention),
or psychological problems.
And remember, the best way to keep hydrated is to listen to your body and drink water when you are thirsty.
It is the best proven guideline when it comes to maintaining your hydration levels.
Thank you for watching
and don’t forget to keep yourself hydrated, in moderation of course.