15 Diseases You Can Prevent Just by Washing Your Hands

Updated: Feb. 15, 2023

To ward off everything from simple respiratory illnesses to the coronavirus, this hygiene basic is the key to keeping you healthy.

Why is handwashing so important?

Put simply, your hands are dirty. As they come into contact with various people, animals, foods, and surfaces, they pick up thousands of germs, bacteria, viruses and other assorted nastiness that can make you sick if they enter your body. “We touch our eyes, noses, and mouths with our hands more than we think, and this can allow direct inoculation of germs into our mucous membranes,” explains Janet Haas, PhD, RN, Director of Epidemiology at Lenox Hill Hospital. “We also use our hands to prepare and eat foods, so hands that are not clean can contaminate foods that we and others will eat.” But washing your hands has the power to minimize or even eliminate those risks—for you and those around you. For example, teaching people about handwashing can reduce diarrheal illnesses in immunocompromised people by up to 58 percent, according to the CDC.

You’re probably washing your hands wrong

Believe it or not, only 5 percent of people wash their hands in a way that actually gets them clean, according to a study in the Journal of Environmental Health. Haas says the trick is to rub soap onto every part of your hands, since the friction is what removes the germs from skin, and to wash for a long enough period of time. “Keep rubbing for 20 seconds, making sure to get soap between fingers and on the backs of hands—and don’t forget the thumbs!” she advises. “Avoid turning off the tap with your clean hands: A towel, a wrist or elbow is preferred to keep your hands clean.” The following 15 illnesses are just a few of the ones that you can prevent with thorough handwashing.


As you likely know by now, people are understandably concerned about the coronavirus, or COVID-19. This new virus can lead to pneumonia, severe acute respiratory failure, and death in some patients, especially the elderly and those with underlying health conditions. According to the World Health Organization (WHO), the mortality rate may be as high as 3.4 percent. Not only can it be transmitted easily via respiratory droplets and have an incubation period of up to 14 days, but people can be asymptomatic carriers—meaning that they can unknowingly pass it on to others.

So, how can you protect yourself and help to slow the spread of this disease? By avoiding close contact with sick people, staying home if you’re not feeling well, and—you guessed it—regularly and properly washing your hands, according to the CDC. This approach has been used to combat various contagions in the past, whether they’re epidemics or pandemics—find out the difference between those two health crises. And recent scientific findings show just how much of a difference hand hygiene can make. According to a new study published in Risk Analysis, proper handwashing at airports could potentially reduce the risk of a pandemic by a whopping 24 to 69 percent. Even if this happened at 10 major airports, the risk would drop by 37 percent. So, yeah, we’d say that’s pretty strong evidence that you should wash your hands—no matter where you are. Learn how much the coronavirus is costing the world so far.


It takes only one norovirus particle to get you sick, as opposed to between 50 and 100 particles of the flu virus. But good, old-fashioned handwashing can help to prevent the assorted gastrointestinal misery that results from a stomach bug. In fact, it trumps both the use of alcohol-based hand sanitizers (which the CDC cautions aren’t as effective against norovirus) and vigorously disinfecting surfaces. According to a study published in Royal Society Open Science, scouring surfaces only reduces transmission by a maximum of 60 percent, while handwashing—if done by a majority of people on, say, a cruise ship—could completely stop an outbreak.

The flu

The flu can be deadly—and not just to those who are very young, very old, or immunocompromised. The 2018–2019 flu season was the longest in a decade, lasting a full 21 weeks from November to April (though the death toll was down quite a bit from 2017–2018). Aside from getting the flu shot, handwashing is a key preventive measure, especially when you’re exposed to flu germs without knowing it. “Every infectious disease has what’s called an incubation period—the time between when you are exposed and when you get sick—and some have a prodrome when you start to feel sick but don’t have signs and symptoms specific to a particular disease,” says Haas. “In many cases, infectious diseases, such as influenza, can be transmitted before a person has signs and symptoms of the disease.” Handwashing can make sure you’re not unwittingly infecting yourself. And you absolutely should wash your hands after touching these dirty surfaces in 12 places you go all the time.

Pink eye

When your eyes get ooey, gooey, and super itchy—and have a crusty coating on them in the morning—you probably have conjunctivitis, aka pink eye. Since people rub their eyes to alleviate the discomfort and then touch their surroundings, the virus or bacteria that cause pink eye ends up on all sorts of surfaces, where it can live for hours or even days, according to the National Institutes of Health. Children are at particular risk for infection and transmission. “Kids explore the world around them in a tactile manner, [so] they are exposed to more potentially contaminated material than adults,” explains Neha Vyas, MD, a family medicine specialist at Cleveland Clinic. “Any viral or bacterial infection can occur in children as a result of this. They are most at risk for eye infections, sore throats, skin infections, lung infections, and genitourinary and gastrointestinal infections.” Teaching proper handwashing techniques early will help them—and everyone around them—to stay healthy now and in the future. One good way to make sure they’re washing their hands enough: Tell them to sing “Happy Birthday” twice as they’re sudsing up.


A big reason to wash your hands more often is that you’re touching poop particles way more than you realize. That’s exactly how salmonella gets passed around. The bacteria lives in the intestines of animals and people, and it’s often transmitted through infected food that hasn’t been fully cooked (meat and eggs) or washed thoroughly (fruits and vegetables); when you don’t wash your hands or equipment after preparing raw meat, poultry and fish; and when you don’t properly wash your hands after using the bathroom or changing a baby’s diapers. It can also be transmitted by touching an infected reptile, amphibian or farm animal, whose droppings can subsequently infect anything they touch. If you’re not diligent about hand hygiene, that could be you. Watch out for these germ-covered things you’re probably carrying right now.


You probably know it as “the kissing disease,” but mono—and the Epstein-Barr virus that causes it—is not only transmitted through kissing. Saliva is the main culprit, so objects that an infected person has sneezed on, coughed on, or touched could subsequently infect you should. Sharing drinks or utensils is also a common way to spread this. If you do come down with mono, you’ll experience extreme fatigue, high fever, body aches, a very sore throat, and an enlarged spleen; symptoms usually last between two and four weeks but sometimes longer.

Hand-foot-and-mouth disease

If you have kids or work around them, handwashing can help prevent this uncomfortable infection caused by the coxsackievirus. Common in daycares and preschools, hand-foot-and-mouth disease (HFMD) causes sores on the mouth and throat, a rash on the hands and feet, a fever and loss of appetite, reports the Mayo Clinic. What gets you sick, exactly? Contagion particles from an infected person’s nose, mouth, blisters, and feces that get on your hands and then into your mouth. Disgusting, we know, which is exactly why you should be washing your hands regularly and teaching your kids to do the same. (Encourage them to keep their hands out of their mouths, while you’re at it.) If you’re pregnant, take particular care since HFMD has been linked to a higher risk of stillbirth near the end of a pregnancy.

child playing with toysgoodmoments/Shutterstock


Here’s another reason to be vigilant about handwashing if you’re pregnant. Good hygiene can prevent the transmission of this virus in the herpes family that can cause serious harm to your unborn child, including hearing and vision loss, intellectual disability, and even death. According to the medical journal BMC Public Health, cytomegalovirus is often passed along through the saliva or urine of young children, and the majority of CMV infections in otherwise-healthy people go undiagnosed. A little soap and water can go a long way in making sure that you and your baby-to-be are okay. Do you know about these things you’re sharing that germ experts wouldn’t?


Caused by a bacteria commonly found on the skin and in the noses of healthy people, staph can become life-threatening if the bacteria gets deep into your body and infects your blood, joints, and heart. Things can get particularly dangerous with an antibiotic-resistant strain of staph called MRSA. “A staph infection may look like a boil or blister, or even just redness on the skin,” says Dr. Vyas. “The stubborn bacterium can live on inanimate objects, such as towels or gym equipment. If you wash your hands, you will lessen the risk of these bacteria being transmitted from person to person.” Other preventive measures include keeping wounds covered and not sharing personal items.


Here’s a crazy statistic from the CDC: Almost all children will have an RSV infection by the time they turn two. The thing is, you will probably just think your child has a cold. But in some children—especially those born prematurely—and in people over 65 with weakened immune systems, this virus can cause breathing problems, pneumonia, bronchiolitis, and death. In fact, it kills more than 200 children each year and 14,000 older adults. Like other respiratory illnesses, coughing and sneezing send infected droplets through the air and onto surfaces.

Hepatitis A

The good news: Hepatitis A doesn’t cause chronic liver disease like its cousins B and C. The bad news: It can still make you really sick, causing gastrointestinal problems, fever, fatigue, and jaundice. In some cases, it can even cause acute liver failure and necessitate hospitalization. You’ll likely hear about hepatitis A outbreaks at restaurants, since this virus is often transmitted when someone hasn’t washed their hands after using the bathroom before preparing your food, according to the World Health Organization (WHO).

Strep throat

While viruses often cause sore throats, if a strep test determines that yours is caused by the bacteria group A Streptococcus, you’ll need antibiotics. Not only can strep throat cause discomfort and be highly contagious to others, but in some cases, it can also lead to scarlet fever, rheumatic fever, a rare kidney disease called PGSN and the pediatric autoimmune disease PANDAS. According to the CDC, coughing, and sneezing spreads small respiratory droplets containing the bacteria. You can’t always stop someone from coughing or sneezing on you, but you can control your own handwashing habits.


While you’re worrying about horrible things that can make you sick, don’t forget about parasites. Handwashing can help to prevent this particular microscopic parasite from taking up residence in your small intestine, where it will cause nausea, diarrhea, and dehydration. Johns Hopkins All Children’s Hospital says that to prevent transmission, handwashing is particularly important before preparing or eating food, after using the bathroom or changing a diaper, and after touching sea creatures in a “touch tank” at the aquarium. Since giardiasis can also be contracted through contaminated water or food, make sure to bring your own water on camping trips (or boil stream water for ten minutes), and wash your fruits and veggies well before eating them. Here are some more foods you should always wash before cooking.

E. coli

We often hear about E. coli outbreaks in terms of food consumption—red meat and romaine lettuce, for example—but it can also be passed by coming into contact with an infected person or animal, according to WebMD. Also, some surprising news: You don’t need to scald your hands with hot water to kill E. coli bacteria—or any other bacteria. Time reports that a recent study published in the Journal of Food Protection found that washing hands in cold, lukewarm and hot water all worked equally well. Plus, people who used lotion regularly had fewer bacteria after washing their hands; that may be due to the lotion’s ability to heal dry, cracked skin, giving germs fewer places to settle in the skin.

The common cold

While not as serious as these other diseases, a cold can still make you feel miserable and ruin your week. One study found that handwashing can lower your risk of catching a respiratory illness by a whopping 45 percent. While this study didn’t explore the effects of hand sanitizers, experts say that they’re great in a pinch… as long as they’re used correctly. According to the CDC, that means using one that contains at least 60 percent alcohol, using the correct amount detailed on the label, and rubbing it in until it’s dry. “They [also] only work well if your hands are pretty clean to begin with and don’t have grease or dirt on them,” says Dr. Vyas. The bottom line: Hand sanitizers have their place and they’re certainly convenient, but in most situations, handwashing should generally be your first line of defense. And there are also plenty of times you’re overusing hand sanitizer.