Ear infections aren’t fun. They can make your ears hot, itchy or painful. They can cause lots of pressure or make it harder to hear. Sometimes fluid leaks out of your ear.
I asked my friend Bevan Briggs why that happens. He’s a nurse practitioner and professor at Washington State University.
He told me people usually get outer ear or middle ear infections.
Your outer ear includes the flappy part attached to your head—called the auricle or pinna. It also includes the ear canal. That’s the tunnel that goes into your head. At the end of the ear canal, there’s a thin, flexible barrier of tissue called the eardrum. That’s the boundary between your outer ear and your middle ear.
“Lots of things can cause an outer ear infection, but it happens a lot when kids go swimming,” Briggs said. “If you’ve ever felt stuff moving around in your ear after swimming, that’s because you have water in your ear touching your eardrum.”
You can tilt your head and gently jiggle your ear until the water falls out. Some people use special ear drops to help dry up the water. If the water stays in your ear, it could make your ear canal the perfect place for bacteria to grow.
Sometimes the bacteria enter your ear with the water—especially if you’re swimming in a river or lake. But there’s always lots of bacteria on your skin and inside your body. So, it could just be your normal bacteria getting out of control. That’s an infection.
If that happens, your immune system will send out fighter cells called white blood cells to kill or gobble up the bacteria. Those cells travel in your blood, so the tiny blood vessels near your ear will become bigger and leaky to let the bacteria-munching cells get where they need to go. That’s called inflammation. It will make the lining of your ear become red and swollen. It’ll probably hurt if you wiggle your ear.
That’s why your nurse practitioner or doctor might give you antibiotic ear drops. They help kill the bacteria and stop the infection.
The other common ear infection happens in your middle ear. That’s the space between your eardrum and your inner ear. It has a drainage tube—called a Eustachian tube—that connects your middle ear to your throat.
“Fluid naturally circulates in the middle ear to keep it clean,” Briggs said. “It drains out of that Eustachian tube. So, if the tube closes, fluid can build up in the middle ear. That fluid can become infected with bacteria, and then inflammation happens. As the white blood cells do their job, you can wind up with this soup of dead white blood cells, bacteria and mucousy fluid—called pus—behind the eardrum.”
But why would your Eustachian tube close? It can happen because of a cold or allergies. It also happens a lot in toddlers, and scientists aren’t sure why. Maybe the size or position of their Eustachian tubes causes a problem until their ears grow.
That’s why some kids need teeny tiny, plastic or metal tubes gently placed in their eardrums. The tube lets trapped fluid and pus drain out of the middle ear. That means fewer painful ear infections while the ears grow.
If you ever feel ear pain or other symptoms of an ear infection, talk to your grownups. The sooner you get help, the sooner you’ll feel—and hear—better.