Between 6-10% of the German population suffers from loneliness, either temporarily or permanently. Loneliness is as harmful as smoking 15 cigarettes a day and is equally detrimental as alcohol consumption. It is even more harmful than a lack of physical activity. It is high time that this phenomenon is comprehensively addressed for health professions. The interdisciplinary book by the experienced editor Thomas Hax explores the topic of loneliness in all its facets. The author team provides a socio-political analysis and examines the subject from medical, psychological, nursing, social science, and theological perspectives. It establishes connections to better assess, recognize, understand, and alleviate experiences of loneliness, consistently linking findings to the fields of work and professional roles of various health professions.