A cancer patient talking nonsense is a sign of aggravation of the disease or the disease is already serious. 1. Cancer patients talking nonsense may be due to brain metastasis of cancer or abnormal brain function caused by primary tumor in the brain, which leads to cancer patients talking nonsense. 2. At the advanced stage of cancer, insufficient blood supply to the brain, weakness and malnutrition will affect the brain function, which will seriously lead to talking nonsense, not recognizing people, consciousness disorder, and even endanger the life. In addition to talking nonsense, brain cancer patients may also suffer from headache, nausea, vomiting, increased intracranial pressure and other such diseases. In order to understand the cause of talking nonsense in late stage of cancer patients, brain CT, cerebral blood flow, blood lipid, blood pressure and other related examinations are needed. Cancer patients need to reflect their condition to the attending doctor in time when they have the condition of talking nonsense, do not blindly give the patient medication, but under the guidance of the physician in accordance with the standardized treatment.