Swimming is great for overall health and fitness but there are times when it is better not to swim and put yourself or other swimmers at risk.
Swimmers should not swim if they have either an open wound which has not healed, an infection which has not yet been taken care of, an airborne disease which can very easily be passed to other swimmers, or conditions like diarrhea and vomiting which can soil the pool water and make it dangerous for other swimmers.
Swimmers should make sure that they use laundered swimwear before going into the pool and that they have showered thoroughly with warm water and soap before immersing themselves into the pool water.
People with open wounds can easily transfer blood borne pathogens into the water and other swimmers in proximity can easily either ingest or expose their skins to such pathogens resulting in potentially harmful consequences. Similarly, people who are suffering from seasonal flu or common cold should stay at home and avoid going to the pool since they have the potential to spread the flu in a public place like a swimming pool faster than any other venue.
Those swimmers who are suffering from diarrhea should avoid going to pool since fecal matter is one of worst offenders in transmitting pathogens to other humans and can result in many more victims including women, children and elderly.
People who are prone to vomiting either due to some sickness or bad food should watch out for such tendencies and should take adequate precautions such as observing their own condition before entering the pool and taking appropriate medication to prevent it from happening while in the middle of swimming.
Swimmers should be also very courteous not to sneeze with an open mouth or spit indiscriminately in the pool water as this is liable to pollute the pool water and create harmful and unsavory environment for other swimmers. If an urge to spit or sneeze arises, swimmers should leave the pool immediately and use a wash basin or shower facility to take care of such situations before reentering the pool.