Learn about these common pool germs and how to prevent and avoid them

Lounging in a hotel cabana and then heading to the swim-up bar, indulging in a refreshing dip during a backyard party, corralling the kiddos to cool off at the community pool — it all sounds nice, right?

Outdoor swimming pools are a summer tradition. But do you know what you’re getting into — literally? Unfortunately, pools can get a bit gross.

Take into consideration this stat: About half (51 percent) of Americans treat pools like a bathtub. In other words, many pool-goers don’t shower before jumping in, even after working out or getting filthy in the yard or… well, you can imagine the possibilities.

All that sweat, dirt, oil, and products like deodorant and hair goop diminish the chlorine-based disinfectant’s power so it’s less effective at keeping the water clean. That leaves swimmers more vulnerable to germs that can cause infection, illness, and irritation.

But you don’t have to resign yourself or your children to sitting on beach towels all season. Summer can still be a big splash if you take a few basic hygiene tips, follow proper swimmer etiquette, and stay on the lookout for funky pool problems.

Being a good pool citizen involves a lot more than not cannonballing near the sunbathers. Whether at a hotel, waterpark, backyard oasis, or community center, your responsibility as a pool patron is to avoid introducing germs or grime into the water. Plus, there are ways to protect yourself from bacteria.

Good pool rules

  • Shower before and after getting in the pool.
  • Stay out of the pool if you’ve had diarrhea.
  • Don’t pee or poop in the pool.
  • Use swim diapers or pants for little ones.
  • Take breaks every hour.
  • Don’t swallow pool water.
  • Check the water with a portable test strip.
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Shower for at least 60 seconds before getting in the pool and scrub up after

Just one swimmer can introduce billions of microbes, including fecal particles, into the water. The good news is that a one-minute rinse is all it takes to remove many of the germs and gunk we want to avoid carrying into the pool. And soaping up after a swim can help remove any icky stuff left on the skin from a dirty pool.

Skip swimming if you’ve had the runs in the last two weeks

According to a 2017 survey, 25 percent of adults say they’d swim within one hour of having diarrhea. That’s a big issue because fecal matter particles on the body get into the water — even more so if you’ve had diarrhea. So, germs like Cryptosporidium which spreads via contaminated feces, can enter the water.

And once someone’s been infected, they can continue to shed the parasite for two weeks after loose stool has stopped. The pesky Crypto parasite can live in pools with adequate chlorine levels for up to 10 days. Keeping yourself and your kid out of the pool after a stomach bug can really help protect others.

Don’t poo or whiz in the water

Kids may need some help with this rule. It’s a common misconception that chlorine will sanitize the pool. In fact, bodily waste degrades chlorine’s germ-fighting abilities. Also, it’s just pretty gross and inconsiderate, especially if you’re not a child and you know exactly what you’re doing. If you witness an incident in the pool, report it to staff right away.

Use swim diapers

Anyone in regular diapers should wear a swim diaper or swim pants in the water. Caregivers should check diapers hourly and change them in restrooms or locker rooms away from the pool area.

Every hour — everyone out!

That’s what the Centers for Disease Control and Prevention (CDC) recommends. This gives you the opportunity to shuttle kids off to the restroom for potty breaks or diaper checks. Good pool hygiene also involves proper wiping and hand-washing after using the toilet.

Don’t swallow the water

Even if you aren’t deliberately swallowing the water, you’re probably still ingesting more than you think. Within just 45 minutes of swimming, the average adult consumes 1 tablespoon of pool water, and kids take in more than twice that much.

Do what you can to minimize what goes into your own mouth. Also, teach kids that pool water isn’t drinkable and that they should close their mouths and plug their noses when going under. Keep plenty of fresh water handy for hydration on breaks.

Pack a portable test strip

If a pool’s chlorine or pH level is off, germs are more likely to spread. If you aren’t sure how clean a pool is, check yourself. The CDC recommends using portable test strips to check if a pool has proper levels before you take a dip.

You can buy strips at many stores or online, or you can order a free test kit from the Water Quality and Health Council.

Don’t worry. Most days spent at the pool will likely end with that contented feeling of having enjoyed some good, old-fashioned fun in the sun. But occasionally stomach upset, ear pain, airway or skin irritation or other issues may crop up.

While it’s not fun to think about pool germs, it helps to know how to prevent infections, what symptoms to watch for, and how to get relief if you do get a recreational water illness.

Common recreational water illnesses

  • diarrheal illnesses
  • swimmer’s ear
  • hot tub rash
  • respiratory infection
  • urinary tract infection
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If you experience stomach issues, you could have a diarrheal illness

Over 80 percent of pool illness outbreaks can be attributed to Crypto. And you can get the runs or experience symptoms from 2 to 10 days after exposure.

Other stomach upset culprits include coming into contact with pathogens such as Giardia, Shigella, norovirus, and E. coli.

Prevention: Avoid swallowing pool water.

Symptoms: diarrhea, cramping, nausea, vomiting, bloody stool, fever, dehydration

What to do: If you suspect you or your child has a diarrheal illness, it’s a good idea to check in with your doctor. Most cases will resolve on their own, but you’ll want to minimize dehydration, which could lead to further complications. Always talk to your doctor if you have bloody stool or a high fever.

Ear irritation after a swim may be swimmer’s ear

Swimmer’s ear is an infection in the outer ear canal. It doesn’t spread from person to person. Instead, it’s caused when water stays in the ear canal for too long, letting bacteria grow and cause problems. Germy pool water is one of the biggest offenders.

Prevention: If you or your child is prone to swimmer’s ear, try swimming earplugs. Your doctor can even custom fit you for them. They may also be able to provide you with ear drops that prevent swimmer’s ear. After swimming, tip the head to drain water from the ear canal, and always dry ears with a towel.

Symptoms: red, itching, painful, or swollen ears

What to do: Call your doctor if you feel like you can’t get water out of your ear or it starts to cause the symptoms above. Swimmer’s ear is usually treated with antibiotic ear drops.

Skin irritation post swim may be ‘hot tub rash’

Hot tub rash or folliculitis gets its name because it commonly appears after you’ve been in a contaminated hot tub or spa, but it can also show up after swimming in a poorly treated heated pool. The germ Pseudomonas aeruginosa causes the rash, and it often appears on skin covered by your suit. So, sitting for hours in that wet bikini can make it a lot worse.

Prevention: Avoid shaving or waxing before taking a dip, and always wash with soap and water and dry yourself thoroughly as soon as possible after being in a hot tub or pool.

Symptoms: red, itchy bumps or small pus-filled blisters

What to do: See your doctor, who may prescribe an anti-itch cream and antibacterial cream.

Painful urination could be a urinary tract infection

Urinary tract infections (UTIs) are another culprit of swimming pool season. A UTI occurs when bacteria travels up the urethra and travels through the urine into the bladder. The offending bacteria can come from icky pool water, not showering after, or from sitting around in a damp bathing suit.

Prevention: Shower after swimming and change out of wet suits or clothes as soon as possible. Drink lots of water throughout your pool adventure.

Symptoms: painful urination, cloudy or bloody pee, pelvic or rectal pain, an increased need to go

What to do: Depending on the cause of the UTI, an antibiotic or an antifungal med will be needed. If you suspect a UTI, talk to your doctor.

Respiratory trouble might be an infection

Legionnaires’ disease is a type of pneumonia caused by Legionella bacteria, which can be inhaled in the mist from pools or steam from hot tubs. It can develop two days to two weeks after exposure to the bacteria, which thrives in warm water.

You can be unaware that you’re breathing in the droplets from the air around a contaminated swimming pool or hot tub.

Typically, contamination is more common at indoor pools, but the bacteria can live outside in a warm, humid environment. It’s more common in people over the age of 50, smokers, and those with weaker immune systems.

Prevention: Use portable test strips to test pools before going in. Smokers have an increased risk of developing it.

Symptoms: chest pain, shortness of breath, fever, chills, coughing up blood

What to do:If you or your child develop respiratory issues after being in a pool, see your doctor right away.

Respiratory problems after swimming may also be a sign of asthma or dry drowning, which is more common in children. If you or someone else is having trouble breathing, call 911.

Luckily, our bodies are outfitted with a pretty good detector for pools that have gone afoul. Basically, if a pool is extremely dirty, your nose will know. But contrary to popular belief, it’s not the strong smell of chlorine that indicates a relatively clean pool. It’s the opposite.

When germs, dirt, and body cells combine with the chlorine in pools, the result is pungent chloramines, which can also get into the air and create a chemical smell. Many people mistake this odor to be an adequately chlorinated pool. Instead, it’s the smell of chlorine being depleted or degraded.

So, if the pool you’re about to get into has an overpowering chemical smell or it irritates your eyes, it may mean it’s extra dirty. Try to avoid it or talk to the lifeguard on duty about the cleaning practices. On the other hand, if it generally smells like a nice summer day, then cannonbaaaaall!

After all this talk of pool germs and what they can do to our bodies, you might be tempted to avoid that cool dip in the pool altogether. We aren’t trying to scare you, but this unpleasant information should inspire you to stick to the hygiene tips and best practices outlined above — and encourage others to as well.

As long as you adopt proper pool etiquette, you’ll keep yourself and everyone else safe.


Jennifer Chesak is a medical journalist for several national publications, a writing instructor, and a freelance book editor. She earned her Master of Science in journalism from Northwestern’s Medill. She’s also the managing editor for the literary magazine, Shift. Jennifer lives in Nashville but hails from North Dakota, and when she’s not writing or sticking her nose in a book, she’s usually running trails or futzing with her garden. Follow her on Instagram or Twitter.