why do we need to pee?


I get that our body needs water. But why does the thirst response almost always overestimates the amount of water our body actually needs, thereby leaving excess water that comes out as urine? How come our body doesn’t tell us to drink just the right amount of water that it needs? Why does yellow pee mean dehydration when the fact that there was enough excess water to produce urine means that you’re probably not dehydrated anymore?

In: 4

Urine and feces are our body’s way of removing toxins and unused food/drinks. In urine, the yellow is the color caused by what’s being excreted. When we drink more water, our urine gets diluted. Hence the more we drink the lighter it gets. Also, our bodies don’t really “over estimate” the amount of water we need. After a certain point, it should stop signaling thirst (unless meds/other health circumstances are relevant).

You flush excess stuff out. Your body constantly disarms, unpacks and processes stuff from hormones to unpacking sugars to throwing out excess hormones.

Which is why we can measure testosterone and ketone levels in pee strips. It is why we use pee as drug testing too. Because if you use performance enhancing drugs some of it will come flushing out.

If your pee is completely clear it just is mostly done for the moment, in fact if you are damn active and drink lots you will notice the pee discolors again. If you just drink lots and then be inactive.. that pee is going to stay clear…because you didn’t particularly do much in the first place.

This is generally a rule of thumb why people say if you drink enough it’s slightly yellowish not fully clear… it is just short hand for “you are kinda active too while drinking enough.”

The waste in urine will crystallize if it gets too concentrated. That can cause kidney stones.

By keeping enough water available, the concentration of the waste products are lower and the system functions better.

Your body doesnt just use the water for keeping water inside. A lot of the water you drink is used to rinse out your system and get rid of water soluable toxins.

Think of urine as the grey water after the janitors are done mopping the floors. Nobody’s drinking that and you want to move the dirt out if the building, so you sump it down the drain. That mop water is more water than anyone was drinking, but it still needed to be brought into the building to be used and then emptied.

Deeply yelow to near brown urine then means you didnt have enough water for mop water, so toxins are staying in your system and not getting filtered properly. Like the mop water getting super black because it was used for three days and never changed.

Basically it’s because your “reservoir of ‘spare’ water” is your blood, but holding water is at the bottom of the list of things that you blood has to do, and it’s a long list with some very critical things on it (oxygen, nutrients for cells, immune system, etc.). So “how much you drink” is controlled in a “better be safe and drink extra than sorry and die of dehydration” way.

It’s also because your kidneys are responsible for removing toxins from your blood, not just water, and they can’t function without also removing water. You can’t pee solids; doing that is called passing kidney stones, and it’s very painful. Yellow pee means your kidneys are forced to concentrate a lot of toxins into very little water to work with, and that’s bad for you (kidney stones again).

Your body IS telling you to drink the right amount of water. If you’re thirsty you will drink; if you’re not thirsty you may drink some (and the body can deal with it), but trying to drink a lot will feel uncomfortable to you as you’re drinking.