Lung adenocarcinoma bone metastasis with increasing pain from radiotherapy may be related to radioactive inflammation, adverse reaction to radiotherapy, and poor radiotherapy effect. Lung adenocarcinoma bone metastasis is a disease caused by metastasis of lung adenocarcinoma to bone tissue with bone pain as the main manifestation. 1. Radiation inflammation: radiotherapy plays an important role in the treatment of lung adenocarcinoma. Palliative radiotherapy for some advanced tumors can achieve the purpose of reducing symptoms, such as pain for bone metastasis, but it cannot achieve the purpose of treatment, therefore, even radiotherapy will have pain. 2. Adverse reaction of radiotherapy: lung adenocarcinoma bone metastasis radiotherapy is getting more and more painful mainly because radiotherapy itself is a process that can cause damage and produce pain. Radiotherapy can not only kill cancer cells, but also kill normal cells in the body, which brings great adverse reactions to the organism, such as nausea and vomiting, fatigue, skin damage, pain aggravation and so on. 3. Poor effect of radiotherapy: some patients with lung adenocarcinoma bone metastasis are not sensitive to radiotherapy drugs, which can not achieve the expected therapeutic effect and cause a series of adverse reactions, such as different degrees of fatigue, dizziness, pain and so on, which seriously affects the quality of life of patients. Lung adenocarcinoma bone metastasis radiotherapy is getting more and more painful, there may be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy.