A person who migrates to and settles in a country other than that of birthplace and upbringing. Immigrants often differ culturally and sometimes in health-related behavior from persons born and raised in the country. Categories include legal immigrants who may acquire citizenship rights (including access to health care, education for their children, and other social benefits); illegal immigrants, who do not have citizenship rights and often work in sweatshops or similar unhealthy conditions; and migratory, itinerant, and guest workers, who have temporary visitor status rather than permanent settler status. These latter groups may not only have health problems of their own, but sometimes may be a health danger to others, harboring contagious diseases such as tuberculosis that screening medical examination identifies in legal immigrants. Migration may be voluntary or involuntary, the latter group being refugees or internally displaced persons. Immigrants often have health problems different from those of the people among whom they settle.