Pleural effusion or clear-fluid pleurisy in the elderly is a frequent complaint in clinical practice. However, it poses a diagnostic and therapeutic problem in view of the clinical polymorphism, delayed consultation and associated comorbidities in this age group.Aging is characterized by a progressive loss of physiological adaptive capacities, due to a reduction in the functional reserves of numerous systems (cardiac, hematological, renal, etc.). This phenomenon is exacerbated by the increasing incidence of co-morbidities and the emergence of geriatric syndromes (dementia, incontinence,...