An understanding of the subjects covered in this article is significant in keeping travelers healthy and comfortable. Each section covers a range of problems and suggestions for their prevention. The areas that are reviewed are: 1) fitness to fly; 2) problems in transit; 3) altitude sickness; 4) marine and swimming hazards; 5) insect precautions; 6) pre- and posttravel care; and 7) illness abroad. An effort has been made to provide practical recommendations as in many cases there is little data and no rules, thus the travel health advisor, with the patients' input, will need to determine the best course of action for each individual and itinerary.