恶病体质(Cachexia)代表因疾病引起的体重减轻以及肌肉量减少，呈现衰落的状态，通常为癌症或爱滋病等严重疾病引起的并发症。

Template:Symptoms concerning nutrition, metabolism and development

Cachexia (from Greek κακός kakos "bad" and ἕξις hexis "condition") or wasting syndrome is loss of weight, muscle atrophy, fatigue, weakness, and significant loss of appetite in someone who is not actively trying to lose weight. The formal definition of cachexia is the loss of body mass that cannot be reversed nutritionally: Even if the affected patient eats more calories, lean body mass will be lost, indicating a primary pathology is in place.