We've all had this happen after a fun day at the pool, right?

You go swimming and you don't get all the water out of your external auditory canal, which is the area from outside your ear right to your eardrum.

Well, that's called swimmer's ear -- or otitis externa -- and it may not be as harmless as we might think!

"Water will typically contain bugs," Dr. Ian Smith explains. "So the bacteria or the fungi will actually live inside of your ear."

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"It's warm and it's moist and they replicate," he continues. "They like that environment."

Based on how your ear canal is constructed, water may even sit in little pockets within the canal.

So, before it gets too comfortable, get that water out as soon as you leave the pool!

How? "The old-fashioned way," the doctor says!

HOW TO GET RID OF SWIMMER’S EAR

Tilt to the side AND move your earlobe around, which helps to change the shape of your canal, thus better allowing water to come out.

(Watch Dr. Ian demonstrate in the video above!)

You can also try to dry the canal out, the doc says, but with nothing smaller than the size of your finger.

(You don't want to poke your eardrum, after all!)

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Now, if your ear starts ringing, producing discharge (which Dr. Ian says is a particularly bad sign), getting red or itchy OR if you stop being able to hear well, those could be symptoms of an infection from swimmer's ear, so take a trip to the doctor!