Q. Can flying on an airplane make you sick? A. "Yes," says Bruce Polsky, chief of the division of infectious diseases at St. Luke’s–Roosevelt Hospital Center, in New York City, "especially if you’re sitting within six feet of someone who is sneezing, coughing, and spewing germs into the dry air." Because the air is recirculated in the close quarters of the plane’s cabin, certain kinds of germs may stay suspended, and you can end up breathing them in. Drink lots of water, and consider using a saline nasal spray to keep your mucous membranes moist.
Q. Can your toothbrush or lipstick reinfect you after you’ve been sick? A. It’s not likely. “If you’ve just come out of a cold, don’t toss it,” says Neil Schachter, a professor of pulmonary and critical care at the Mount Sinai School of Medicine, in New York City. “Once you’ve had a particular viral illness, you’re protected from it.”
Q. Can you get sick from touching a doorknob? A. Yes. Germs last longer than you think. “Viruses can survive up to three days on surfaces and inanimate objects,” says Chuck Gerba, a professor of environmental microbiology at the University of Arizona in Tucson. That’s why it’s a good idea to carry your own pen. To reduce the number of germs, be sure to zap hot spots (the phone, for instance) regularly at home and at work with a disinfecting product, such as Clorox Disinfecting Wipes.
Q. Can you catch the same cold or flu twice in the same season? A. You can’t get exactly the same one, as your body will have developed antibodies to it. But “cold and flu viruses mutate, so there are subtly different forms of the virus,” says Caroline Rudnick, an assistant professor of community and family medicine at St. Louis University. “Getting one type doesn’t protect you from another.” Even if you’ve had the flu vaccine, if a different strain of the flu virus is going around, you could catch it.
Q. Is it safe to exercise with a cold? A. "Do a 'neck check': If your symptoms are in or above your neck―say, if you have a stuffy nose, a headache, and a mildly sore throat and you’re sneezing―it’s fine to work out," Schachter says. "But if your symptoms extend below the neck―if you have a cough, a fever, body aches, or chills―take a break from exercising until you feel better."
Q. Can going outside with wet hair in the winter make you sick? A. Exposure to an infection, not cold temperatures, can make you sick. “But if your body gets cold, it could get physically stressed because it’s using a lot of energy to try to stay warm, and you might be more likely to catch an infection,” Rudnick explains. To avoid stressing your body unnecessarily, dry your hair before going out in the cold, or wear a hat.
Normally your body’s barriers, including your skin and the linings of your airways and gastrointestinal tract, keep invaders out. But low immunity, contact with a heavy germ load, high stress, and some surprising factors can increase your chances of getting sick.
Having fewer illnesses in childhood could affect your health as an adult. Paradoxically, people who were frequently sick with viral infections as children typically have greater immunity and are susceptible to fewer infections as adults. “Antibodies last a lifetime,” says James A. Wilde, an infectious-disease specialist and the director of the pediatric emergency department at the Medical College of Georgia, in Augusta. When your child is sick with her third cold of the season, remind yourself that it may be helpful to her in the long run.
Cold temperatures and low humidity, indoors and out, can irritate or damage your airways. Air pollution, indoor dust, and ash from fireplaces can also act as irritants, causing inflammation and making it easier for germs to enter your system, says Russell Robertson, chair of the department of family medicine at the Feinberg School of Medicine at Northwestern University, in Chicago.
Smoking can make you prone to bacterial and viral infections. “Smoking damages the linings of the nose and throat, which not only offer barrier protection but also have a coating of fine filaments, called cilia, on the surface,” says Neil Schachter, a professor of pulmonary and critical care at the Mount Sinai School of Medicine, in New York City. That’s why smokers tend to have more frequent and worse colds than nonsmokers. Exposure to secondhand smoke can also lower your natural defenses.
Stress, lack of sleep, and poor nourishment can also set you up for getting sick. Stress and fatigue can lower your resistance to infection and increase the intensity of illnesses you do get. (For more on how stress can make you sick, see Manage Your Stress.) But there may be a bit of a lag between a stressful event and when you become ill. “When you’re in a period of maximal stress, you’re releasing a lot of adrenaline, which keeps you going,” says Bruce Polsky, chief of the division of infectious diseases at St. Luke’s–Roosevelt Hospital Center, in New York City. “Once that stressful stimulus is over or removed, you crash.”
If you’re under long-term stress, you’re especially susceptible to illness, because chronically elevated stress hormones can suppress immune function and lower the activity of germ-fighting white blood cells. Researchers at Carnegie Mellon University found that severe chronic stress―from such things as conflicts with family or friends and unemployment―significantly increases a person’s risk of coming down with a cold.
Strengthen your body’s defenses by eating well, drinking lots of water, exercising regularly, and staying away from people who appear sick. If you do get a bug, pamper yourself.
Eat antioxidant-rich foods, such as whole-grain cereals, walnuts, and artichokes, as well as foods packed with omega-3 fatty acids, such as salmon. “The antioxidants protect the body’s tissues against stress and inflammation and enhance immune function,” says Cindy Moore, a registered dietitian and the director of nutrition therapy at the Cleveland Clinic. “Omega-3 fatty acids promote blood flow and the production of anti-inflammatory substances,” which also boost immune function.
Take a brisk walk every day. Any kind of moderate daily exercise―such as cycling, swimming, or working out at the gym―can improve lung and immune function. Physical activity enhances the ability of T lymphocytes (white blood cells that attack virus and cancer cells) to ramp up the immune response, says Neil Schachter, a professor of pulmonary and critical care at the Mount Sinai School of Medicine, in New York City. But don’t push yourself too hard. Some studies suggest that high-intensity exercise for two or more hours at a time increases stress hormones, which can lead to suppression of the immune system.
Stay three or more feet away from people who are coughing or sneezing. This will keep you outside the immediate spray of their germs, says Chuck Gerba, a professor of environmental microbiology at the University of Arizona in Tucson. Wash your hands frequently and thoroughly. If you’re not near a sink during the day or you work in a high-germ environment, such as a school, carry an alcohol-based hand sanitizer with you.
As you’ve been told millions of times, drink lots of water, don’t skimp on sleep, and get a flu shot. The tried-and-true advice still holds. Staying well hydrated keeps the tissues of the respiratory system moist and helps the immune system work properly. Sleep helps the body function at an optimum level. If you get seven to eight hours of rest a night, you’ll be less likely to become sick, and if you do catch something, you’ll recover faster. October through November is the best time to be immunized, even if you’re a healthy adult. If you can’t stand needles, ask your doctor about FluMist, a prescription nasal-spray vaccine that’s as effective as a shot.
Finally, stay home from work when you first feel ill. It’s possible that work-related stress (not to mention commuting) could slow your recovery. Tell your boss that Real Simple said so.