Sarcopenia, which is defined as a decrease in skeletal muscle mass and strength with aging, is an important risk factor in clinical medicine that is associated with mortality, and poor surgical and nonsurgical outcomes. Sarcopenia is now recognized as a multifactorial geriatric syndrome. Cachexia is defined as a metabolic syndrome with inflammation as the key feature, so cachexia can be an underlying condition of sarcopenia. Recently, cachexia has been defined as a complex metabolic syndrome associated with an underlying illness and characterized by the loss of muscle mass with or without a loss of fat mass. These two conditions overlap but are not the same. In clinical practice, many factors related to sarcopenia (decreased food intake, inactivity, and decreased hormones) are reported frequently in patients with cachexia. On the contrary, systemic inflammation, the core feature of cachexia, can also be present in apparently healthy older sarcopenic patients. This suggests that new therapeutic approaches, alone or in combination, may be appropriate in both conditions.