Lung cancer in advanced stage may indirectly cause patients to develop cerebral thrombosis. Patients with advanced lung cancer usually have metastasis of cancer cells, and if patients have brain metastasis, which leads to the appearance of cancer cells in the cranium, in this case, cancer clots will appear in the blood vessels of the brain, thus causing cerebral blood clots. In addition, some elderly patients with advanced lung cancer usually have high blood sugar and blood fat, and their blood viscosity is also high. After long-term anti-cancer treatment, it will lead to further increase of blood viscosity, which is likely to lead to cerebral thrombosis and other diseases in lung cancer patients. When patients have lung cancer, they must go to the hospital for treatment in time and pay attention to the emergence of other complications at the same time.