The causes of sudden wasting include the following: 1, diabetes, diabetes patients usually show three more and one less symptoms, one less refers to weight loss, that is, wasting; 2, hyperthyroidism, hyperthyroidism patients may show wasting due to increased basal metabolic rate, but hyperthyroidism patients usually also have fear of heat, sweating, hand trembling, emotional impatience and anxiety and other accompanying symptoms; 3, tumors, especially digestive tract tumors, may affect the tumor metabolism increase, which in turn affects food absorption, prone to the performance of wasting.