Travel Health 2Go Reason2Go Health Information for Travelers Spring 2017 Health Risks and Precautions for International Travelers General Considerations The number of people traveling internationally increases every year. International tourist arrivals in the year 2015 reached 1 billion, with arrivals expected to reach 1.6 billion by 2025. Over half the arrivals were for leisure and holidays, with business, religious pilgrimages, and family visits cited as other major reasons people travel. International travel can pose serious health risks to travelers, depending on the destination country, the nature and characteristics of the trip, and the traveler's physical condition and overall health. Travelers might be exposed to sudden and significant changes in altitude, humidity, microbes, and temperature. Also, serious health risks can arise in areas where clean water is unavailable, sanitation and hygiene are inadequate, and medical services are not well-developed