Your kid experiences many new things as they head back to school: New teachers. New classrooms. New germs ...

As a parent, you of course hate to see your child sick — not to mention what it can mean for you and the rest of your family if they've brought something contagious home. But how much can you really do to help keep your kid from getting sick as they head back to school?

"Illness, to some extent, is a reality of being a part of a community," says Dr. Donald Brown, an internal medicine hospitalist at Houston Methodist. "Many different germs can spread from person to person and cause illness, but there are also many steps we can take to help prevent this."

The most common illnesses kids pick at school

The illnesses that kids frequently bring home from school are caused by infectious microbes — usually viruses, though bacteria make the list, too.

Some of the most common ones to spread as kids go back to school include:

• Colds
• Stomach flu, also called viral gastroenteritis
• Pink eye
• Strep throat

These illnesses spread easily from person to person, usually through close contact, so they can quickly move through classrooms and, if your child takes one home, your family.

"Other illnesses that kids can easily pick up at school include the flu and COVID-19," says Dr. Brown. "Flu season doesn't typically peak until the winter, but COVID-19 cases have been increasing lately. Parents should be aware of this as kids head back to school."

5 ways to help prevent back-to-school illnesses

No matter how careful we are, illnesses happen. But here are five ways Dr. Brown says you can help prevent your child from getting sick at school.

1. Explain that germs are always hiding

The tricky thing about germs is that, while we can't see them, they're essentially everywhere — in the air, on surfaces and more. You'll want to explain this to your child, and you'll also likely need to remind them periodically.

"It's also helpful to outline the places they're most likely to encounter illness-causing germs, such as in bathrooms and on high-touch surfaces or items," says Dr. Brown.

(Related: Germs: The Most Likely (& Sometimes Surprising) Places to Find Them)

The frequently touched surfaces and items that can be loaded with germs include:

• Door handles
• Light switches
• Toilets
• Handrails
• Countertops
• Handheld electronics
• Shared toys

This isn't to say your child shouldn't touch these things of course. But it's important for them to know when prevention steps, like handwashing, are most important.

2. Reinforce the healthy basics

As you send your kids back to school, remind them of the steps that help prevent the spread of germs, including:

• Regular handwashing, especially before eating, after using the bathroom, and sneezing, coughing or blowing your nose
• Avoid touching your face or putting your hands in your eyes, nose and mouth
• Cover coughs and sneezes, ideally doing so into a tissue and disposing of it in a waste bin
• Avoid close contact with people who are sick

Dr. Brown notes that, in particular, it's important that your child understands what it takes to make handwashing effective at preventing the spread of germs.

"Certain steps need to be followed," explains Dr. Brown. "Wet your hands, scrub with soap and water for 20 seconds and then dry your hands thoroughly. Not scrubbing long enough and not completely drying hands are the common mistakes people make, especially kids."

If soap and water aren't available, hand sanitizer — containing at least 60% alcohol — can be used as a substitute.

3. Know how to support your child's immune system

To avoid getting sick, take steps to help your child maintain a strong immune system by:

• Prioritizing nutritious foods – limiting ultra-processed foods and eating plenty of vegetables, fruits, legumes, whole grains, lean proteins and healthy fats
• Being physically active – current guidelines are for children and adolescents to get at least 60 minutes of physical activity every day
• Drinking plenty of water – consider sending your child to school with a water bottle
• Getting quality sleep – know how much sleep your child needs and enforce a consistent bedtime, even on weekends
• Minimizing stress as much as possible – warning signs your child might be stressed include lack of motivation, physical exhaustion, irritability and other uncharacteristic mood states

"As a parent, it's important to strive to be a role model of these behaviors," says Dr. Brown. "Eating nutritious meals and snacks, scheduling time to be active as a family, encouraging open communication — these are all things you can do to help set an example of what a healthy lifestyle should look like."

(Related: 10 Tips for Managing a Healthy Household)

4. Stay up-to-date on recommended vaccines

Also key to building a strong immune system is making sure your child is current on the available vaccinations that help prevent illnesses.

"Your family medicine practitioner will let you know if your child is due for any immunizations," says Dr. Brown. "They will also check in on your child's overall health and can be a great resource for any unanswered questions you might have."

A common one right now is whether your kid might need a COVID-19 booster.

"It's a conversation to have with your child's doctor, since the answer varies based on age, which shots they've already received and whether they're immunocompromised," says Dr. Brown. "Generally speaking, no new shots are recommended for children who are already current on COVID-19 vaccinations, but this could change as updated boosters are scheduled to become available this fall."

5. Keep your child home when sick

Last but not least, preventing illness also means knowing when your kid shouldn't go to school.

Symptoms suggesting your child might have an infectious illness include:

• Having a fever over 100.4 F, or having had one within the last 24 hours
• Malaise, such as unexplained fatigue and weakness
• Vomiting and diarrhea
• Excessive coughing
• Yellow or green drainage from the eye(s)

"No parent wants to hold their child out of school unnecessarily, but the common illnesses that spread through schools can be very contagious," says Dr. Brown. "If you suspect your child is sick, it's best to be cautious since this can help keep teachers and other students healthy."