Fever in the advanced stage of lung adenocarcinoma may be cancerous fever caused by tumor itself, or it may be caused by bacterial, viral and other infections. 1. Carcinogenic fever: In advanced stage of lung adenocarcinoma, the tumor grows faster and the blood supply of the tumor can not guarantee the growth of the tumor tissue, which leads to ischemic necrosis of the tumor tissue, and the absorption of necrotic tissue will cause the body to become feverish. Secondly, some tumor tissues will secrete some cytokines, which will stimulate the body temperature center to produce more heat and cause fever. 2. Bacterial and viral infections: patients with advanced stage of lung adenocarcinoma are easy to suffer from bacterial, viral and parasitic infections due to malnutrition, lowered resistance and poor physical quality, which will cause fever. After the symptoms of fever appear in the advanced stage of lung adenocarcinoma, patients should go to the hospital in time, improve the examination, and give targeted treatment after clarifying the cause of the disease.