The reasons why papillary thyroid cancer is always wasting are as follows: 1. papillary thyroid cancer combined with lung metastasis, bone metastasis, etc., which causes heavy tumor load and overconsumption, but papillary thyroid cancer is less malignant and generally less likely to occur; 2. papillary thyroid cancer combined with hyperthyroidism, hyperthyroidism causes excessive metabolism, which causes overconsumption; 3. The hyperthyroidism causes the body to consume too much, and even the hyperthyroidism is combined with diarrhea, which causes excessive consumption and wasting; 3. Papillary thyroid cancer is combined with other diseases, such as diabetes mellitus, and diabetic patients drink more, eat more and urinate more, resulting in wasting. Therefore, patients with papillary thyroid cancer need to identify the causes of wasting so that effective treatment can be carried out.