A refugee is a person who is unable or unwilling to return to their country of nationality (or country of last habitual residence) because of persecution or a well-founded fear of persecution on account of race, religion, nationality, membership in a particular social group, or political opinion.
Many refugees are exposed to brutal or unjust conditions in their own country (war violence, lack of accessible education, lack of medical care, and more), and when they migrate, they are again exposed to new threats to their wellbeing known as "core stressors".