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Why is handwashing so important, and how does it help prevent the spread of disease?

December 18, 2020

Remember when you were a kid and your mother asked you if you had washed your hands before having dinner or after going to the bathroom?

There was a good reason for asking.

Your mom probably wanted you to stay healthy and keep others healthy, too.

“Proper hand hygiene is the single most important means of preventing sickness and the spread of infection,” said Kristin M. Smith, an infection control practitioner at Baystate Medical Center.


Good personal hygiene begins and ends with our hands. Unwashed hands are one of the quickest ways we can spread germs and cross-contaminate items around our home.

The American Medical Association offers several principles of hand awareness – wash your hands when they are dirty and before eating, do not cough or sneeze into your hands, and don’t put your fingers in your eyes, nose, or mouth.

According to the Centers for Disease Control and Prevention (CDC), handwashing can prevent 1 in 3 diarrhea-related illnesses and 1 in 5 infections, including the flu and COVID-19.

“I can’t stress enough the importance of hand washing to reduce the spread of germs,” said Dr. Megan Gallagher of the Infectious Disease Division at Baystate Medical Center. This is especially true during flu season and the current COVID-19 pandemic.

How does handwashing prevent illness and infection?

Simply put, soap removes germs from your hands. Washing your hands with soap is one of the most important public health practices for slowing the COVID-19 pandemic and also protecting you from many different types of infections. 

According to the CDC, handwashing can prevent about 30% of diarrhea-related sicknesses and about 20% of respiratory infections (like colds). Soap works not by killing germs but by removing them from your hands. Lathering and scrubbing creates friction, which helps lift germs from your skin.  


The CDC suggests the following key times to wash your hands:

  • Before, during, and after preparing food
  • Before eating food
  • Before and after caring for someone at home who is sick with vomiting or diarrhea
  • Before and after treating a cut or wound
  • After using the toilet
  • After changing diapers or cleaning up a child who has used the toilet
  • After blowing your nose, coughing, or sneezing
  • After touching an animal, animal feed, or animal waste
  • After handling pet food or pet treats
  • After touching garbage  
  • After you have been in a public place


Make sure you know how to wash your hands correctly to help fight the spread of germs and infection. The five steps to proper handwashing are:

  1. Wet your hands with clean, running water (warm or cold), turn off the tap, and apply soap.
  2. Lather your hands by rubbing them together with the soap. Be sure to lather the backs of your hands, between your fingers, and under your nails.
  3. Scrub your hands for at least 20 seconds. Need a timer? Hum the “Happy Birthday” song from beginning to end twice.
  4. Rinse your hands well under clean, running water.
  5. Dry your hands using a clean towel or air dry them.

While washing your hands with soap and water is considered the best way to eliminate germs, the CDC recommends using an alcohol-based hand sanitizer (at least 60% alcohol) if soap and water are not available. When using hand sanitizer, be sure to cover all surfaces, including between fingers and the tops of hands. Remember, however, that sanitizers do not get rid of all types of germs, harmful chemicals, and grease.

By following these tips and practicing good hand hygiene, you are keeping yourself and others healthy.

Learn more about COVID-19 prevention