Eli5: Why do we NEED to drink water?


I just don’t understand it enough to motivate me to drink enough. Hoping to “see” something in the explanations that will open the floodgates. 🙂

In: Biology

Water to us is like oil to a car.

It keeps our body in working order.

Also a nice glass of ice cold water is fucking tasty when you’re thirsty.

Because it’s necessary for your body to function properly and it’s constantly being lost due to sweat, urination, and other factors; thus, you need to regularly replenish it. It’s so critical that you will die faster from lack of water than you will from a lack of food.

Because if you don’t you get sick and die? Is that not reason enough?

Just so you know, most of the stories that say you need six or eight or ten glasses of water a day are bullshit. You should drink water if you’re thirsty; that’s how your body tells you you need water. If you feel fine, you’re fine. That’s all there is to it.

A lot of the chemical reactions in your body requires water.

Do note that when you hear recommendations about drinking X glasses of water a day a lot of that comes from the food you eat, drink when you’re thirsty

Your body is made up of around 60% of it.

It uses water as a solvent to clean out dirt and grime.

It combines water with other things to make lubrication for your joints.

Your blood cells cannot travel without it and without it your blood becomes a sludge that your heart can’t move.

Your eyes are only round because of the water inside them. Without water, you could not see.

You use water to balance as well, little tubes in your ears use water like the accelerometer in your phone to be able to tell where down is.

You need water to breathe safely as it helps filter out pollutants in the nose and even the throat.

You need water to eat, otherwise your throat would be so dry food would stick to it and you would choke.

You need water to move as electricity moves through fluid the nerves are coated and surrounded in and the muscles would be dry and brittle otherwise.

You need water to keep your skin flexible instead of stiff and hard like leather.

You need water to even survive! Your brain – containing all that you are and will be – is basically a sea slug in a calcium jar. It sits in a carefully balanced and carefully pressurized mix of water and other things we call Cerebrospinal Fluid. Since it is about the same density as the brain – which itself is mostly water – it helps hold the brain in place and protect it from impact. It helps prevent collisions with the skull. It keeps the brain wet so that electricity and chemicals and all sorts of things can move through it and allow you to learn and think and grow and flow through the world like the water-based being that you are.

We never truly left the sea… We just learned how to take it with us.

We use water for literally everything. We are water with some stuff holding it in. Our cells are mostly water. Blood is over 90% water, accounting for the water in blood cells. All the liquids we produce – sweat, mucus, tears, etc. – require water. Less eli5, water is the medium in which chemical reactions happen in our bodies.

We need to drink water because it’s constantly used. We lose the water we sweat. We have to constantly replenish our tears and saliva as liquid evaporates on our eyes and in our mouths. A ton of water is used to expel waste. Our cells divide and they need more water as they grow (this is actually huge, about 2/3 of the water in our bodies is in cells.)

You are water. Without water, you’re a vaguely humanoid husk.

Edit: to get a grasp of how important and prevalent water is in organisms on earth, to simplify equations, we commonly approximate the density of living things to the density of water. We are meat. Meat is water. You are water.

>motivate me to drink enough

Just wondering what you mean by “enough”. The advice that you need to drink “x amount per day” is not correct. The amount is different per person and stuff like coffee, soda etc DOES count to keep you hydrated. Also electrolytes are equally important to keep you hydrated.