Pool water can make you sick with illnesses like diarrhea, hot tub rash, swimmer's ear, or Legionnaires' disease. The symptoms of a swimming pool illness may include a fever, pain, or skin irritation.
You may have heard stories about people who pick up germs from swimming. Don't panic. Most of these recreational water illnesses are mild and easily treated. Here are some of the most common ways swimming can make you sick and what you can do to protect yourself and your family.
How Long After Shocking a Pool Can You Swim?
You can pick up germs from swimming in a pool, hot tub, lake, ocean, or river. There's a chance you can get sick if you swallow, come into contact with, or breathe in mist.
It's important to disinfect pools and hot tubs with chlorine or bromine to prevent the spread of germs. The following groups of people are more at risk for swimming-related illnesses:
- Children
- People with a weak immune system or who take medication that affects their immune system
- Pregnant people
- Those who have an underlying health condition
1. Diarrhea
Diarrhea is one of the most common swimming-related illnesses. Once the water has been contaminated by germs that cause contagious diarrhea, a swimmer only has to swallow a tiny amount to become infected. Germs like Cryptosporidium, Giardia, Shigella, norovirus, and E. coli can be transmitted anytime someone who's sick with diarrhea (or has been sick in the last two weeks) enters the water.
Cryptosporidium (crypto) is the most common cause of pool-related diarrhea outbreaks. Crypto can stay alive for days, even in pools treated with chlorine and other chemicals. That's why public pools require you to shower before taking a dip. Stay out if you've recently been sick to keep the pool safe for everyone.
It may be a good idea to steer clear of swimming in lakes or rivers that aren't monitored for safety. Animals in the water can also pass on these germs.
Diarrheal illnesses transmitted through the water can last two weeks and cause serious, sometimes even life-threatening, dehydration. Call a healthcare provider if you have:
- Black stools
- Diarrhea that lasts more than 24 hours (in children)
- Diarrhea that lasts two days or more (in adults)
- Fever
- Severe abdominal pain
- Signs of dehydration, such as dry mouth, headache, and infrequent urination
- Stools with blood or pus
Water contaminated with the bacteria Pseudomonas aeruginosa can cause hot tub rash, a type of skin irritation. Germ-killing chemicals like chlorine break down faster in hot water, hence the higher risk posed by hot tubs and the ailment's nickname. This bacteria can also be spread in poorly maintained pools or contaminated lakes.
The longer your skin is exposed to contaminated water, the more likely you are to get hot tub rash. The safest thing to do is shower as soon as you get out of the pool.
You can check the water yourself using the pool and hot tub test strips. You can also ask if your hot tub is checked regularly for proper disinfectant and pH levels.
Hot tub rash, which usually appears as itchy, red, bumpy spots or pus-filled blisters, usually goes away on its own in a few days. Call a healthcare provider if a rash lasts longer than that.
3. Swimmer's Ear
Otitis externa—more commonly known as swimmer's ear—happens when water gets trapped in the outer ear canal. The trapped water causes bacteria or fungi to grow. It's more common in children than adults.
Symptoms include itching, pain, and swelling. Pus may drain from the ear in some cases. See a healthcare provider if you think you have a swimmer's ear. You may need antibiotics to treat it.
Ways to prevent swimmer's ear include:
- Dry your ears thoroughly after swimming with a soft towel
- Run a hair dryer on low heat a few inches away from your ears
- Tilt your head from side to side and pull gently on your earlobe to help water escape
You can also buy ear drops at the drugstore that help dry out the ear canal after swimming. Check with a healthcare provider before using them.
Germs that live in hot tubs or pools can also infect people who breathe in steam or mist coming off the water. The bacterium Legionella, which causes the lung infection Legionnaires' disease, sometimes spreads this way.
Legionella is found naturally in water, especially warm water. Making sure that a pool or hot tub is properly cleaned and disinfected—either by asking or by testing it yourself—can reduce your risk of becoming infected.
Legionnaires' disease can cause any of the following symptoms:
- Chest pain
- Cough
- Diarrhea
- Fever
- Headaches
- Muscle aches
- Nausea
- Shortness of breath
See a healthcare provider if you suspect you've been exposed. Legionnaires' disease is usually treatable with antibiotics when diagnosed early, but it can sometimes be fatal. It's most dangerous to older adults, as well as those who smoke, have chronic lung disease, or have a weak immune system.
A Chlorine Rash Might Make Your Skin Feel Itchy After Swimming in a Pool
A Quick Review
It's possible to get sick from swimming in a pool, lake, river, or hot tub. Swimming-related illnesses include diarrhea, hot tub rash, swimmer's ear, and legionnaires' disease. The best way to prevent swimming-related illness is to keep your mouth closed when swimming and dry your ears out after swimming.
Avoid swimming if you or your child has been sick with diarrhea within the last two weeks. See a healthcare provider if you experience concerning symptoms of a swimming-related illness.
