Sarcopenia is a progressive and generalized skeletal muscle disease that causes accelerated loss of skeletal muscle mass and function. The prevalence of sarcopenia in the community is about 10% globally but about 12% in China. Sarcopenia is associated with the decreased numbers of motor neurons and satellite cells,and muscle loss resulting from factors including aging, hormonal deficiencies, chronic inflammation, mitochondrial dysfunction,nutritional deficiencies, and physical inactivity. The diagnosis of sarcopenia is made based on the lower muscle mass and decreased muscle strength with or without reduced physical performance. Its treatment includes non-pharmaceutical and pharmaceutical options. The former includes resistance exercise, blood flow restriction training, and nutritional supplementation, but effects of medications lack evidence. Early diagnosis and intervention of sarcopenia can reduce the occurrence of adverse outcomes. This review focuses on the epidemiology, pathophysiology, diagnosis, and treatment of sarcopenia.