You can get a serious respiratory illness

What your mother always said is true: If you don't wash your hands, you're going to get sick. You can get the common cold, yes, but the risks are much more severe than that. The flu, pneumonia, adenovirus, and even hand, foot, and mouth disease are all respiratory illnesses you can develop from neglecting to wash your hands, according to the CDC. Good handwashing practices can cut the number of colds and respiratory illnesses you contract by 16 to 21 percent—that's why handwashing is one of the 20 secrets from people who never get sick. 

You can get diarrhea

Diarrhea-related illnesses can strike easily in people who don't wash their hands. Tanya McIntosh, an infection-control practitioner at the University of Kansas Medical Center, says, 'Handwashing after you go to the bathroom is another key time to perform hand hygiene. Bacteria and viruses from feces (poop) can cause various diarrhea-related illnesses, including salmonella, norovirus, and E. coli 0157.' The CDC reports that the simple act of handwashing reduces the number of people who get sick with diarrhea by 31 percent.

You can get (and give) food poisoning

Another time when handwashing plays a key role in avoiding illness? When you're cooking. McIntosh cites frequent washing as essential to preventing cross-contamination. 'Foods such as raw meat, vegetables with dirt on them, or eggs can harbor potentially harmful bacteria that can make you sick if not handled correctly,' she says. Find out the 9 things food poisoning experts never eat.

You can infect other people

Remember, your hands are touching pretty much everything around you throughout the day. This means that when you touch a doorknob after touching your eyes, mouth, nose, or face, you're putting whoever touches it after you at risk of picking up your germs. And likewise, when you touch that doorknob, you're also picking up the germs of everyone who touched it before you. If that creeps you out, wait until you see the 15 everyday items that are dirtier than a toilet seat.

You could be putting people with weak immune systems at risk

According to anesthesiologist Christian Whitney, DO, a pain management consultant for Restorative Pain Solutions, 'The risk of not washing your hands is that you could get exposed to potentially harmful infections and also infect others, especially young infants, the elderly, and those that are immuno-compromised and susceptible to infections.' In other words, by not washing your hands after going to the bathroom, or touching potentially contaminated foods, you can create huge complications for those around you who have weaker immune systems. Minimize the risk by being vigilant about washing your hands.

You could be contributing to antibiotic resistance

Handwashing is the most important step in not catching an infection in the first place, so doing it regularly can reduce the number of infections that are spread—infections that are often treated with antibiotics. The CDC reports that handwashing can prevent about one-third of diarrhea-related illnesses and about one-fifth of respiratory infections. It can also reduce by almost 60 percent the spread of diarrhea-related illnesses in people with weakened immune systems. Fewer infections mean less widespread antibiotic treatment, and the overuse of antibiotics is the leading cause of antibiotic resistance. Washing your hands can also prevent the spread of difficult-to-treat illnesses from germs that have already become resistant to antibiotics.