Sarcopenia is an aging syndrome with multiple contributing factors, characterized by a loss of muscle strength, function and mass. It affects a third of the elderly population, increasing morbidity and mortality, as well as health costs. It should be suspected in the event of a decrease in physical capacities reported or observed during the consultation, in a patient with risk factors. Five questions (SARC-F formulary) or the measure of the gait speed makes screening easy to perform ; the diagnosis is confirmed by supplementary examinations in a specialized center. Treatment consists on performing physical exercises against resistance and ensuring sufficient caloric and protein intake; drug treatments are under study.