weight loss symptoms ICD9CM_2005:783.21 SYMP:0000476 SYMP:0000178 UMLS_CUI:C0043096 A weight symptom that is characterized by a reduction of the total body mass, by a mean loss of fluid, body fat (adipose tissue), or lean mass (namely bone mineral deposits, muscle, tendon, and other connective tissue). Weight loss can either occur unintentionally because of malnourishment or an underlying disease. UMLS_ICD9CM_2005_AUI:A1605347 loss of weight weight symptom