A 20-second way to prevent illness is to wash your hands properly. Knowing when and how to wash your hands will help you avoid sickness from the flu along with a number of diseases. It seems simple enough, but you'd be surprised to find out many people are washing their hands all wrong.

Children often are taught at a young age to wash their hands—before eating and after using the restroom. It’s an easy and effective way to stay healthy and avoid spreading disease.

But Dr. Gregory Poland, director of Mayo Clinic’s Vaccine Research Group, says adults could do much better at the sink.

“People go to the bathroom, and they run their fingers under the water. Well, that does nothing. And then they grab the dirty faucet, and they touch the dirty handle on the way out of the bathroom.”

Dr. Poland says that, in public washrooms, there are often more bacteria on those faucets than in the toilet water.

Next time you’re at the sink, Dr. Poland says, "Wash your hands while singing 'Happy Birthday' to yourself. You get between the fingers, the fingertips, the thumb. You turn the water off with a paper towel. And you open the door to leave with a paper towel and dispose of the paper towel. That’s how you wash your hands—ideally with warm, soapy water.”