Travel increases during the holidays, coinciding with cold and flu season. Being cooped up in a plane with strangers coughing and sneezing their way through the flight, along with the added stress of travel and its potentially dampening effect on the immune system, can leave you vulnerable to illness.

Not only are your fellow passengers’ germs health hazards, but changes in air pressure, humidity and oxygen concentration in the cabin can exacerbate chronic medical problems, says Dr. Divya Chauhan, a family physician at Creve Coeur Family Medicine and on staff at St. Luke’s Hospital. Spraying planes with chemicals like insecticides and de-icing agents also can leach some vapors into the cabin, potentially aggravating some conditions.

However, your greatest threat may be sitting right behind you. “While we frequently hear about stale air circulating throughout the plane, most transmitted illness has been found to come from persons within two rows of the air traveler,” says Karen Moore, coordinator of the Adult-Gero Nurse Practitioner program at Saint Louis University and an expert in travel health for BJC Travelers’ Health Service. “The challenge is that we, as travelers, have no control over the health of those around us, so good attention to hand hygiene and cough hygiene are very important.” Frequent hand-washing, coughing into one’s bent elbow (instead of hands) and avoiding hand-to-face contact will help reduce spread of communicable diseases.

“Airborne and other over-the-counter products have long made claims of preventing illness and boosting immunity in the absence of any supporting data,” notes Dr. Richard Ihnat, a physician specializing in internal medicine with the SSM Medical Group at St. Mary’s Health Center. “Airborne, in particular, paid a $30 million fine for deceptive advertising related to their unsubstantiated claims. The best way to stay healthy during the winter are the basic things like eating a balanced diet, exercising and getting enough sleep. Also, receiving a flu shot each year can reduce your chance of getting influenza by 70 to 80 percent.”

Chauhan notes that some especially susceptible travelers may want to use a medical-grade face mask to cover the mouth and nose. “You can also use your own pillows, blankets and headsets, if possible. Those items get cleaned regularly, but there is no way to know if germs may be embedded in the material,” she adds.

Medical professionals also cite the risk of deep vein thrombosis (DVT) when on extended flights. Sitting in one position for hours increases the risk of a blood clot forming in the leg and then potentially traveling to the heart or lungs.

“While multiple studies have been done to determine the true risk of DVT to the healthy air traveler, the results have been inconclusive,” Moore says. “Travelers who may wish to take extra precautions to prevent DVT would be the frequent traveler, the traveler on long flights (greater than four hours) or travelers with health conditions or medications that alter blood flow such as estrogen-containing medications, obesity, pregnancy, cancer, congestive heart failure or Factor V mutation.”

DVT prevention includes hydration with non-caffeinated beverages, standing and walking every hour or so on long flights, and trying to stretch your legs and rotating or pumping the ankles to maintain blood circulation.

If you have chronic health conditions, see your primary-care physician four to six weeks before you travel. All travelers can visit the Centers for Disease Control and Prevention’s website,, with specific health tips and warnings related to various destinations.

More Health-wellness articles.