Always coming back from vacation feeling sick? Here's why — and how you can avoid it.

It’s like clockwork: You start settling into your daily routine after a fun weekend getaway when all of a sudden you notice you’ve got a case of the sniffles. Why is it that whenever we leave town for a few days, we often come back feeling unwell — and needing even more time off to recover? Is it the travel that's making you ill? And, if so, what's the best way to avoid catching something?

Dr. Laura Purdy, a family medicine physician and medical director of Swell Medical, says coming home with a cold or other bugs is fairly common due to the exposure you have and the activities you do while traveling. Planes, airports, buses and taxicabs are all spaces that put travelers in close contact with infected individuals, she says.

“Close passenger contact is almost unavoidable, and you are sitting in the same seats without them being cleaned between passengers, which makes the likelihood [of getting sick] higher,” Purdy tells Yahoo Life. How we spend our time also matters. “Concerts, sporting events and other activities are common places to catch a cold because of the large number of people in one given space at one given time.”

Dr. Jim Evans, a travel doctor with Allianz Partners USA and co-founder of SentinelMED, tells Yahoo Life that travel can also disrupt one’s sleep hygiene as well as their diet and the amount of physical activity they typically get, which can also make them more susceptible to catching colds and other bugs.

“Moving from one climate where your body and immune system are used to operating into another, different environment also can challenge your immune system and make it more susceptible to infection,” he adds.

And while it might seem like you’re coming home to a cold every time you return from a trip, Evans says this might have more to do with the incubation period of the common cold and other respiratory viruses. "Viral symptoms can have a slow, insidious onset, so it can sometimes take a week or more to even notice that you're coming down with something," he says.

That said, while you might feel like you’re coming down with something, that’s actually not always the case. For one, it could be allergies.

“Sometimes the change in pollen and local environment may trigger allergy symptoms that feel like a cold,” says Dr. S. Wesley Long, medical director of Diagnostic Microbiology at Houston Methodist Hospital.

You might also just be feeling the effects of fatigue. “Oftentimes when you are on vacation you are all ‘go go go,’ and when you finally come home, it all stops and you ease back into your typical routine,” says Purdy. “This can ... create fatigue and the feelings of being worn down after a trip as you finally settle.”

But there are ways to try to reduce your odds of coming home ill. Read on for expert tips to avoid colds (and more) on your next vacation.

Keep your hands clean

Experts agree that important to stay on top of our hygiene when it comes to our hands.

“One common source of infections can be high-touch surfaces — things like door handles or common-use items that may not be cleaned often. As such, frequent handwashing with soap and water can help prevent illness transmission via that route,” says Long.

It's also worth packing some supplies for those times when you can't get to a sink or need to wipe something down. “Consider carrying hand sanitizer and microbial wipes to use on your airline tray table, arm rest and other surfaces that are frequently contacted by other people,” says Evans. “The luggage bins at the TSA checkpoints also come to mind.”

Watch the people around you

Whether you're waiting to board your flight or are roaming a museum with a tour group, it's worth taking a look around. “Be mindful of standing next to people who are showing signs of illness like coughing and sneezing,” says Purdy. Germs love proximity, so do your best to stay away from those who are noticeably sick.

Wear a mask

Of course, we can’t always choose where we sit or who we're next to. Maybe you’re at a ticketed event where you can’t change seats. Or worse, you’re on a flight and someone in your row won’t stop coughing. That’s when our trusty masks come into play.

“Wearing high-quality, well-fitting masks can help prevent respiratory virus transmission, especially in crowds,” Long says. Studies have shown that masks help reduce the spread of airborne pathogens, from colds and COVID, among others

Drink water

Hydration is important for overall health, and Evans suggests drinking plenty of water while traveling. This goes double if you’re taking any flights, as airplanes can dehydrate you.

Both he and Long also suggest using bottled water, particularly in areas where the tap water may not be safe to drink. Additionally, you might want to reconsider accepting any iced beverages. “Remember that ice may be made in some cases from the local water supply,” says Long.

Consider bringing along your smart watch and other helpful travel accessories

“Smart watches and wearable fitness trackers can help monitor your activity levels and sleep,” says Evans. If you set reminders on them (like ones to move at least every few hours, or get a certain number of steps in daily), you’ll be better able to stay on top of our fitness routines while on the road.

Other items Evans recommends tossing in your suitcase? Mini UV sanitizers, which can be used to keep your phone and other devices clean, glasses (or sunglasses) for eye protection and portable air purifiers for use in your hotel room.

Stay on top of your vaccines

While there are no vaccines for colds, many other illnesses can be avoided if you stay up to date on your shots.

“If you are traveling internationally, you may want to consult with a travel medicine physician to obtain required vaccines as well as advice on specific local infectious disease hazards,” says Long.

COVID-19, pertussis (aka whooping cough) and varicella (chicken pox) are just some of the vaccinations you can get to reduce your odds of getting sick and greatly reduce your chances of serious illness.

Avoid the crowds

And, finally, experts agree that travel during off-peak times and away from larger groups is always recommended if you're trying to avoid getting sick. If you’re visiting busy attractions like museums and theme parks, try going on a weekday.