A wide variety of factors increase or decrease the risk of disease, injury and death. Diet, sanitation and basic health care, including immunization and simple first aid have the greatest impact on the risk of acquiring a disease or surviving it. Lifestyle, type of employment, sex, age, climate, location of home, type of transportation used, amount of exercise and sleep, type of personality, race, and many other factors known and unknown increase the chances of disease and injury.
A World Bank study showed that workers who were sent overseas made significantly more insurance claims for infections and minor physical illnesses such as backache than those who did not travel. The study also showed that these workers were twice as likely to make insurance claims for psychological damage. Those who made two or three overseas trips a year were 3 times as likely to make such claims. Men who travelled made 80 per cent more overall health claims than men who did not, while women travellers only made 18 per cent more. The reasons given in the study for the increased stress of workers who travelled included the long hours most workers put in while abroad, the pressures of increased responsibilities, and dealing with the work at home which piled up during the traveller's absence.