Brain metastasis of lung adenocarcinoma is generally an advanced stage of cancer, which is a more serious and scary condition. Lung adenocarcinoma is the most common type of lung cancer in China. Generally speaking, early lung adenocarcinoma has a chance to be cured through surgery. If metastasis occurs, it is generally more serious, among which brain metastasis is more serious. In the early stage of brain metastasis, patients may not have any related symptoms, but may also have central nervous system symptoms, such as headache, vomiting, dizziness, ataxia, hemiplegia, epilepsy, etc. Sometimes, mental status change and visual impairment may also occur. In serious cases, it is more likely to lead to brain hernia due to tumor compression, which is life-threatening. Therefore, it is suggested that lung adenocarcinoma patients must have timely treatment and regular review. Once brain metastasis occurs, patients should actively cooperate with doctors for treatment to help prolong life and improve survival quality.