The collective monograph for the first time summarizes the experience of world literature and materials obtained by scientists of the Siberian Branch of the Academy of Medical Sciences of the USSR, Finland and several other Scandinavian countries in the field of northern medicine. An ecological assessment of the northern regions is given, the characteristics of the vital activity of healthy human populations represented by the indigenous and newcomer populations of the Asian North of the USSR, the Arctic regions of Finland and Greenland are considered. Optimal ways of rehabilitation for residents of the Far North are outlined, taking into account the experience of biomedical research in the USSR and Scandinavian countries.