Lung adenocarcinoma bone metastasis may cause knee pain. Lung adenocarcinoma bone metastasis belongs to the advanced stage of lung adenocarcinoma, and the cancer cells metastasized to the bone may cause knee pain. Generally speaking, knee pain can be divided into pain at the primary lesion of the knee and pain caused by lung cancer metastasis. 1. Knee pain from primary lesion: It may be caused by previous injuries, cysts in the knee area or connective tissue disease, etc. Knee pain may occur. Diclofenac diethylamide emulsion, ibuprofen, etc. can be used under doctor’s guidance. 2. Pain caused by metastasis of lung cancer: pain caused by metastasis of lung cancer. After bone metastasis of lung cancer occurs, the metastasis oppresses the local tissues, which may cause knee pain. You can use ibuprofen and pethidine to relieve pain under doctor’s guidance, or cooperate with doctor for radiotherapy treatment. Postoperative diet of lung adenocarcinoma needs to pay attention to low fat, high protein and balanced nutrition, while maintenance requires patients to pay attention to keeping warm, avoiding cold and avoiding oily and smoky environment after surgery.