Common Recreational Water Illnesses and How to Prevent Them

Swimming is usually safe, but there is a small chance of getting sick from swimming in unclean water. Recreational water illness (RWI) includes many waterborne infections in different organ systems in your body. The most common symptom is diarrhea.

Since the 1990s, there has been an increase in RWIs. Anyone involved in recreational water use should be aware of the risk.

This article explains how someone gets sick, symptoms, treatment, and how to prevent RWIs.

Three kids jumping into a lake

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Common Symptoms

  • Diarrhea: The most common RWI symptom is diarrhea. Diarrhea can be caused by cryptosporidium (commonly known as "crypto") and escherichia coli (E. coli).
  • Hot tub rash or dermatitis: These rashes are usually raised, red, and itchy. The worst areas are often those that were not covered by a bathing suit. The most common germ that causes a hot tub rash is pseudomonas aeruginosa.
  • Ear pain: Pseudomonas aeruginosa can also cause swimmer's ear. Swimmer's ear can occur in adults and children but is more common in children. Other common symptoms include swelling, redness, itchiness inside the ear canal, and ear drainage.
  • Upper respiratory symptoms: These can include cough, sinus congestion, or flu-like symptoms. A less common and more serious complication is severe pneumonia from Legionella (legionnaires' disease). It may be life-threatening and should be treated with antibiotics.

How Recreational Water Illnesses Are Contracted

RWIs occur when you accidentally swallow, inhale, or get water in your ears that contains bacteria. It may also enter through cuts or open sores. Contaminated water can be found in mountain streams and lakes, hot tubs, public pools or water parks, and oceans.

It is important to understand that chlorine does not kill RWI germs right away. Warm water in hot tubs may help bacteria grow. Also, the process of passing air through the water jets in a hot tub may lower chlorine levels.

Once the water source is impure, it can take chlorine minutes or even days to kill the bacteria. Even a little contact with the germ can cause you to become sick. Children, pregnant women, or people with weakened immune systems are most at risk.

RWIs are not usually spread from person to person through direct contact, such as touching, kissing, or most sexual contact. For example, it is not possible to give swimmer's ear to someone else.

You can share diarrhea-causing parasites through fecal matter if you don't wash your hands after using the restroom.

Rashes from hot tubs and swimming pools are generally not contagious. However, if you have diarrhea and then get in a swimming pool, you will contaminate the water. This makes it much more likely that someone else will get a RWI.

Some illnesses like methicillin-resistant Staphylococcus aureus (MRSA) do not live long in chlorinated water. These are more likely to be passed from person to person through indirect contact, such as using the same towel or by touching other shared objects.


People catch RWIs by taking in bacteria from water. This happens by inhaling, swallowing, or getting water in the ears. Sometimes bacteria enter through open cuts. These kinds of infections are not spread person to person through direct contact. However, some bacteria can enter the water from one person and spread through that water to another person. This is the case when someone has diarrhea and enters a pool.


Some RWIs can be treated with antibiotics or antifungal medications. Others will go away on their own and only need symptom management for comfort or to prevent dehydration.

Swimmer's ear is treated with antibiotic drops or acetic acid drops that must be put inside the ear.

Seek medical attention when symptoms start to get proper treatment and avoid serious complications. The length of the infection will vary by the germ causing it and whether or not antibiotics or anti-fungal medications can be used.


RWIs are treat with antibiotics or antifungals depending on the germ. It is important to contact your healthcare provider as soon as symptoms appear to avoid complications.


Prevention is very important. Swimmer's ear is easier to prevent than some other RWIs. You may not always be able to prevent an RWI, but you should do all you can to try to prevent the spread. This will decrease the amount of other people who get RWIs and your chances of getting one.

Listed below are some prevention techniques:

  • Shower with soap before and after swimming, and practice good hand hygiene.
  • Check and maintain proper chlorine levels in personal swimming pools and hot tubs.
  • Don't go swimming when you or a family member has diarrhea. Wait two weeks before swimming after you've had a diarrhea-causing illness.
  • Take your children regularly to the bathroom when using recreational water facilities. Children who are not potty trained should wear a certified swim diaper plus plastic pants.
  • Don't swallow pool water or drink untreated natural water such as stream water.
  • Don't get into a swimming pool or hot tub if you have open cuts or sores.
  • Dry your ears out well or wear earplugs to keep your ears dry while showering or swimming.

If you think you have gotten sick from swimming see a medical professional as soon as possible.


RWIs are more common now than in previous years. There are many germs that can spread illness in water. The most common symptoms are diarrhea, rash, ear pain, and upper respiratory symptoms. If you experience any of these symptoms, it is important to seek medical attention to get the correct treatment. Treatments can include antibiotic or antifungal medications.

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  • Diarrheal Illness. CDC website. Updated
  • Ear Infections. CDC website.
  • Recreational Water Illnesses. CDC website. Updated January 25, 2017.