There’s nothing worse than being sick, except being sick far from home. And it happens a lot because travel can be tough on your health, especially during the winter holidays.

Several factors come into play, including stress, disruption of normal sleeping patterns and dietary changes. But the biggest threat is being in close proximity with other people, say experts.

“The risk of getting a respiratory infection is about six times greater for people taking mass transit than traveling alone,” notes Charles Gerba, a professor of microbiology at the University of Arizona.

In his research, Gerba took samplings from the hard surfaces of several commercial airliners, and he found that the most germ-infested areas were seat trays and bathrooms.

“The worst restroom you can use is an airplane toilet due to the high use and fact that people don’t wash their hands in there as much,” Gerba tells Newsmax Health. “If you’ve got a good bladder, your best bet is to hold it in during the flight.”

Seat trays also harbor a host of germs.

“Nobody disinfects those trays between flights, and the planes are loading and unloading several times a day,” says Gerba. “So you wind up with a lot of germs there. We found influenza virus, norovirus, which causes diarrhea, and others. We found (antibiotic-resistant) MRSA on every plane we tested.”

Armrests, headrests, seat pockets and the latches on overhead bins are other areas of concern. Experts also say to avoid aisle seats because people tend to steady themselves on them while walking to and from the bathrooms.

Gerba suggests using both disinfectant wipes and hand sanitizers to help protect yourself. He adds that you should try to keep your fingers away from your nose, mouth, and eyes because they are the portals for cold germs to enter your body.

It may come as a surprise to hear that airborne bugs aren’t as big a threat. Studies show that high-efficient particulate air (HEPA) filters remove 99.97 percent of airborne particles in planes, including bacteria and viruses.

“Due to the way the air circulates, you only have to worry about people coughing or sneezing if they’re sitting next to you, directly in front of you or directly behind you,” says Gerba. “And try to avoid sitting next to little kids. They’re germs’ best friends.”

Don’t be shy about asking people to cover their mouths when they cough or requesting a seat change. You should also keep your air vent open to blow the bugs somewhere else.

“The studies show if you do three things — wash your hands, use hand sanitizers, and use disinfectant wipes — you can reduce risk of getting an infection by 50 percent,” says Gerba.

Here are some other things that can affect health while traveling:

Stress: Whether going by planes, trains, or automobiles, traveling presents a lot of stress that can weaken your body’s defenses. Try to keep this in mind as you wait in security lines, search for lost luggage or get lost while driving in an unfamiliar city.

Experts say a few deep breaths will do wonders, and stress-busting adaptogenic herbs such as ginseng, ashwagandha, and rhodiola might help. When all else fails, remember that any crisis on the road is likely to become either a funny story or valuable life lesson in time.

Sleep: Whether it’s a 6 a.m. flight, jet lag or just too much late-night partying, travel can wreak havoc on your normal sleeping habits, and studies show a tired body is more susceptible to sickness. Taking supplements with melatonin, a hormone that helps regulate the circadian rhythm, has been shown to help people adjust to jet lag.

Other things you can do include bringing your own pillow to offer a comfort from home, and using a sleep mask and/or earplugs to aid your slumber in disruptive environments.

Food: Seeing how airport and airplane food is often overpriced and nutrient-poor, some dieticians recommend packing your own food for a flight. And while people tend to overindulge while on vacation, remember that good nutrition provides your body with the tools it needs to fight off infections.

Go ahead and enjoy the waffle-cake, but make sure to get your fruits and veggies too. Also, be aware that food-borne illness has ruined many a vacation, so make sure restaurants are clean and food is thoroughly cooked.