Table of Contents
Effects on Circulation. Traveling by car, airplane, or train for more than four hours increases the risk for blood clots in the legs (deep vein thrombosis, also known as DVT) in anyone. Those at highest risk include people with cardiovascular disease or its risk factors, people who have had recent surgery, cancer patients, and those taking oral contraceptives. Studies now suggest that DVT is the cause of more deaths than previously believed, because symptoms typically occur days after travel. In order to keep circulation moving during international flights or on trains, travelers should drink plenty of fluids, avoid salt, wear slippers, wear clothing that fits loosely in the waist and legs, take frequent walks in the aisles, and lift their legs up and down several times an hour. Two 2003 studies suggested that special stocking that compress the calves and ankles (such as Kendall Travel Socks, Sigvaris Traveno) may significantly prevent swelling and possibly blood clots due to long flights, even in travelers at medium to low risk.
Respiratory Infections. Flight cabins have very low humidity, which not only increases the risk for dehydration and dry eyes, but it also increases the risk for triggering disease in the airways. Fliers with colds or allergies are especially susceptible. The first rule is to drink plenty of liquids. Taking a decongestant tablet or nasal spray (not one containing an antihistamine) 30 minutes before flight can help prevent sinus and ear infections.
Of greater concern are studies suggesting that the prolonged time (8 hours or more) spent in the confined space of an airplane, combined with the close proximity to passengers from around the world, may facilitate the spread of serious contagious diseases such as tuberculosis. The CDC and World Health Organization now have guidelines on when and how to determine the need for preventive treatments after possible exposure to infectious organisms. (Recirculated air, which is now common in new aircraft, does not increase the risk for respiratory infections.)
Preventing Jet Lag. Crossing time zones can throw off the body's natural rhythms, especially when travelers fly from west to east. But jet lag can be minimized. A few days before long flights, adjust sleeping and eating patterns:
- When traveling west, travelers might avoid outdoor light after 6 p.m.
- If traveling east, travelers might begin going to bed earlier a few days before the trip and avoid outdoor light until 10 a.m.
- If possible, flights should be completed well ahead of an important event requiring concentration.
- If crossing multiple time zones, the traveler should schedule overnight stopovers.
- The traveler should drink plenty of fluids, but avoid alcohol and coffee, which increase fluid loss.
Melatonin, a natural hormone associated with light changes, may help people recover from jet lag. Some people report good results by taking it on the day of departure a half hour before the expected sleeping time in the arrival city. Travelers might also ask their doctors about short-acting benzodiazepines ("sleeping pills") such as lorazepam (Ativan); benzodiazepine-receptor agonists such as zolpidem (Ambien) or eszopiclone (Lunesta); alprazolam (Xanax); or temazepam (Restoril). Note that these drugs have been known to cause short-term forgetfulness and other side effects, and should be tested out at home before traveling.
Cruise Ships
Reports of illnesses aboard cruise ships, particularly gastrointestinal problems from contaminated food, have alarmed many travelers. A sanitation program conducted by the U.S. Public Health Service should significantly cut the risk for such problems. Cruise ships are inspected twice a year and are then rated. The CDC provides ratings to the public for all ships sailing from U.S. ports. At this time the ratings are the only guide for a healthy cruise. Meanwhile, cruise-ship travelers should avoid eating eggs and shellfish to help protect against diarrhea.
Aside from sanitation, health problems in general are common on cruise ships. A study of one major cruise ship reported that nearly 30% of the passengers were treated for skin disorders and 26% for respiratory problems while on board. The highly contagious norovirus, brought on board by one passenger, can quickly spread throughout the ship. Flu outbreaks sometimes occur even in summer. Older people who have not been immunized the previous flu season should ask their doctor about flu vaccinations. They add no value for people who had been previously immunized.
Preventing Skin Disorders
An estimated 3 - 10% of travelers experience some skin problem related to their trip, particularly when traveling to tropical and subtropical areas.
Avoiding Excessive Exposure to Sunlight. Many developing countries are in the tropics, were sunlight is intense. Ultraviolet radiation from sunlight not only can cause sunburn, but excessive sunlight and heat can cause toxic skin reactions in susceptible individuals. Everyone should avoid episodes of excessive sun exposure, particularly during the hours of 10 a.m. to 4 p.m., when sunlight pours down 80% of its daily dose of damaging ultraviolet radiation. Reflective surfaces like water, sand, concrete, and white-painted areas should be avoided. Clouds and haze are not protective. High altitudes increase the risk for burning in shorter time, compared to sea level and lower altitudes. Sunscreens and sunblocks with an SPF of 15 or higher are important and should be used generously. However, they should not be relied on for complete protection. Wearing sun-protective clothing is equally important, and provides even better protection than sunscreens. Everyone, including children, should wear hats with wide brims.
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Review Date: 01/30/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine,
Harvard Medical School; Physician, Massachusetts General Hospital.
Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M.,
Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
