An easy action that takes just 20 seconds can cut your risk for catching a cold, flu or other contagious diseases by up to 51 percent, recent studies show. And if everyone made it a regular habit, one million deaths a year would be prevented, according to the Centers for Disease Control, which calls this habit the single most important way to avoid spreading infection.

Frequent hand washing with soap and water can save you money—and misery—by helping you avoid medical bills, missed workdays, or having to stay home with a sick child. And you’ll also protect your friends and family: A CDC survey found that 40 million Americans a year fall prey to illnesses spread by hands, which can harbor up to 500,000 bacteria per square centimeter.

The 11 Germiest Places in Your Home

Not only does lathering up protect you from respiratory illnesses like colds, but it also helps ward off more serious conditions, including hepatitis A, meningitis, and potentially life-threatening superbug infections, such as MRSA. Overall, 80 percent of all infectious diseases are spread by touch.

Here are just a few research findings that illustrate the protective power of clean hands:

    Kids who washed their hands four times a day had 25 percent fewer school absences due to contagious diseases and 57 percent fewer sick days due to GI bugs.
    When 40,000 Navy recruits were instructed to wash their hands five times a day, their rate of respiratory infections fell by 45 percent, according to a study published in American Journal of Preventive Medicine.
    A 2011 study found that when students disinfected their hands three times a day with ethanol gel sanitizer, there was a 66 percent drop in pupils who missed four or more days due to illness and a 20 percent rise in students with zero absences, compared to data from the previous year.
    Hand washing reduces risk for colds and other respiratory illnesses by 21 percent, according to the CDC.
    Washing with soap and water lowers risk for diarrhea and severe or fatal intestinal infections by up to 59 percent, a systematic review published in Lancet reported.