The cause of fever in the afternoon of advanced stage of lung adenocarcinoma is considered to be due to the combination of infection or tumor fever of advanced stage patients. 1. Fever caused by infection factor, most of the immunity of patients with advanced lung adenocarcinoma is in low state, so it is very easy to be infected with lung and other parts of the body, which will cause fever in the afternoon, and need to be given sensitive antibiotics, and the commonly used antibiotics are ceftriaxone, moxifloxacin, piperacillin and tazobactam. 2. Lung adenocarcinoma tumor factor causes fever, advanced lung adenocarcinoma tumor rapid proliferation causes tissue necrosis and absorption and other factors triggering fever in the afternoon. Generally speaking, most of the patients with fever caused by tumor fever have body temperature not more than 38.5 degrees, and the effect of antibiotics is poor, and indomethacin and other medicines are often chosen to deal with the symptoms and reduce the body temperature. Drugs need to be used under the guidance of a doctor, avoid self-medication.