How to Wash Your Hands—Properly

[Originally published: March 13, 2020. Updated: Jan. 17, 2025]

It may be the most frequently repeated advice for avoiding illness, and it’s a simple one: Wash your hands. “Among the many infection prevention practices available to doctors, good handwashing has made the single biggest impact on infection transmission and resulted in savings millions of lives,” says Arjun Venkatesh, MD, MBA, MHS, chair of emergency medicine for Yale Medicine.

Good handwashing—with the help of soap and the friction of rubbing hands together—is a strategy that can minimize germs, or pathogens that cause disease. Handwashing is a key preventive strategy for norovirus, the most common cause of “viral stomach flu.”

“The most common mistake made when it comes to handwashing is forgetting to do it in the first place; the second most common mistake is doing it so fast that you don’t get every part of both hands,” says Dr. Venkatesh.

Here are handwashing tips from the Centers for Disease Control and Prevention (CDC) and Yale providers.

• Use clean, running water to wet your hands. The water can be cold or warm—cold water actually does work and warm water is more likely to irritate skin.
• Rub your hands with soap (and rub your hands together to lather the soap).
• Lather both the front and back of your hands, in between all of your fingers, under the fingernails, thumbs, and up to the wrist.
• Wash your hands for at least 20 seconds—about as much time as it would take to sing the Happy Birthday song twice from start to finish. (But keep in mind that a thorough cleaning—the friction, how intensely you rub your hands together—is more important than time spent washing hands.)
• Dry your hands completely. You can dry them under a warm air dryer, or use a paper towel. Avoid a recently used towel as moisture is a good breeding ground for bacteria, which makes drying your hands an important step.

According to the CDC, you should wash your hands before and after preparing and eating meals, when caring for another person who is sick, after using the bathroom, after coughing or sneezing, after changing a diaper, before and after treating a cut or wound, after touching an animal or anything animal-related (including pet food and pet treats), or any time your hands are dirty.

Antibacterial hand sanitizers aren’t as effective as soap, and they don’t work well against norovirus, which has a capsule around the virus that protects it against most routine disinfectants. For norovirus, vigorous washing with plain soap and water is much more effective.

But for many other viruses, if you are in a situation where you don’t have access to soap, it is better to use an antibacterial hand sanitizer (look for one that contains at least 60% alcohol) than nothing, according to the CDC. (Contrary to a popular myth, alcohol-based sanitizers do not cause antibiotic resistance.)

For viruses other than norovirus, “using alcohol-based hand sanitizers properly can be almost as good as using soap and water,” says Dr. Venkatesh, “but you must be sure to use enough sanitizer to cover both sides of your hands, in between digits, and under nails while also allowing enough time for your hands to completely dry—about 20 seconds—before touching anything. Do not wipe off any hand sanitizer or try to use a towel to dry it as that can cancel any benefit.”

Yale Medicine emergency medicine specialist Sharon Chekijian, MD, MPH, also recommends washing your hands frequently throughout the day, and especially at home. “You should make your home your 'safe zone.' Have all household members wash their hands when they return from the outside world. Make a habit of wiping down surfaces, including counters, doorknobs, remotes, light switches, and especially your phone,” she says.

In the end, keeping your hands clean is a key strategy for avoiding germs, staying healthy, and keeping those around you safe as well.