Why Do I Sometimes Pee So Much?

I’m at the movies with a friend.

It’s getting near the very end.

And that is when it comes to me:

I really, really need to pee!

Yet sometimes when I go to play,

and I am out for half the day,

I never seem to have to pee.

So, Dr. Jo, how can that be?

Now, you already know the scoop:

digestive waste comes out as poop.

But some digestive waste that’s small

does not come out this way at all.

These smaller wastes will slowly go

through organ walls into blood flow.

Then kidneys clean your blood all day

to send these smaller wastes away.

Your kidneys both work constantly

to filter blood and make your pee;

your urine is the way that you

get rid of blood waste passing through.

Your body’s needs determine which

things in the blood your kidneys ditch.

Some things you need in small amounts,

but not too much—and that’s what counts.

Each kidney has a way to track

what’s in the blood, and then hold back

things cells might need, if they’re too low;

or if they’re high, it lets them go.

Like salt: it’s needed by each cell,

but with too much, they won’t do well.

Plus water: this you clearly need,

but when there’s too much, it gets peed.

So, at the movies, you might think

you’ll quickly gulp a giant drink.

But one thing you don’t think about

is extra soda must come out!

The urge to go comes rapidly

as kidneys turn soda to pee.

This fills your bladder up so then

you have to squeeze to hold it in.

Yet on a hot and sunny day,

things may work just the other way.

You run around and sweat and then

lose lots of water through your skin.

So now your kidneys compensate:

they make less urine. You can wait—

you’ll run and jump and catch that ball

and never think of pee at all.

COOL FACTS ABOUT URINE

• Capuchin monkeys have a funny way of getting a good grip on things: they engage in a behavior called “urine washing.” The monkeys urinate right onto their hands and then rub the smelly liquid on their feet. Any water in the monkey’s urine will quickly evaporate, or move from the skin into the air. What’s left behind is a sticky, salty mix that helps the monkeys hold on tightly as they climb and jump around in the trees.

• A squirt of urine is a good way for a male porcupine to tell if a female is willing to mate. Since the sharp, spiky quills of a porcupine can be very dangerous, even for another porcupine, it is important for the male suitor to find out if she will allow him to come near. To do this, the male stands on his hind legs and shoots a stream of urine at her. If the female likes the scent of his urine, she’ll allow him to come mate with her.
• Male butterflies are often found sipping other animals’ urine. The butterflies will gather in groups to drink from a urine-soaked mud puddle. They stick their long proboscises, or mouthparts, into the puddle and sip, often for hours. Other “yummy” fluids butterflies sip from may contain tears, decaying animals, and feces. This behavior is called puddling. It provides the males with salts that they then can give to females during mating. The salts are important for the growth and development of butterfly eggs.