Lower respiratory tract infections (LRTIs) are the most important drivers of hospitalization and antibiotic overuse. Due to ageing and changes in societal structure, patients with LRTI and low medical risk are hospitalized primarily based on psychosocial and functional factors, co-morbidities and anticipation of complications. Hospitalizations are associated with accelerated functional decline and nosocomial complications. An early, comprehensive and adequate risk assessment combining medical, biopsychosocial and functional approaches will optimize patient care and the allocation of limited hospital beds and health care resources. Two of the CALC gene superfamily of peptides, procalcitonin (PCT) and proadrenomedullin (ProADM), appear to be superior diagnostic and prognostic tools.