who may develop cachexia. In the effort to better classify cachexia severity, several scoring systems have been proposed including the Cachexia Staging Score (CSS) and Cachexia Score (CASCO). The CSS takes into account weight loss, subjective reporting of muscle function, performance status, appetite loss, and laboratory changes to categorize patients into non-cachexia, pre-cachexia, cachexia, and refractory cachexia. The Cachexia SCOre (CASCO) is another validated score that includes evaluation of body weight loss and composition, inflammation, metabolic disturbances, immunosuppression, physical performance, anorexia, and quality of life. Evaluation of changes in body composition is limited by the difficulty in measuring muscle mass and health in a non-invasive and cost-effective way. Imaging with quantification of muscle mass has been investigated including bioelectrical impedance analysis, computed tomography, dual-energy X-ray absorptiometry (DEXA), and magnetic resonance imaging but are not widely used. Definition Identification, treatment, and research of cachexia have historically been limited by the lack of a widely accepted definition of cachexia. In 2011, an international consensus group adopted a definition of cachexia as "a multifactorial syndrome defined by an ongoing loss of skeletal muscle mass (with or without loss of fat mass) that can be partially but not entirely reversed by conventional nutritional support." Cachexia differs from weight loss due to malnutrition from malabsorption, anorexia nervosa, or anorexia due to major depressive disorder. Weight loss from inadequate caloric intake generally causes fat loss before muscle loss, whereas cachexia causes predominantly muscle wasting. Cachexia is also distinct from sarcopenia, or age-related muscle loss, although they often co-exist. Treatment The management of cachexia depends on the underlying cause, the general prognosis, and the needs of the person affected. The most effective approach to cachexia is treating the underlying disease process. An example is the reduction in cachexia from AIDS by highly active antiretroviral therapy. However this is often not possible or maybe inadequate to reverse the cachexia syndrome in other diseases. Approaches to mitigate muscle loss include exercise, nutritional therapies, and medications. Exercise Therapy that includes regular physical exercise can be recommended for the treatment of cachexia due to the positive effects of exercise on skeletal muscle but current evidence remains uncertain as to its effectiveness, acceptability and safety for cancer patients. Individuals with cachexia generally report low levels of physical activity and few engage in an exercise routine, owing to low motivation to exercise and a belief that exercising may worsen their symptoms or cause