Uremic brain is the end stage of chronic renal failure, so the patients will have clinical manifestations of various systems during this period, and the earliest symptoms are those of the digestive system. Patients have nausea, vomiting, loss of appetite, and in severe cases, peptic ulcers, gastrointestinal bleeding, patients show abdominal pain, vomiting blood, black stools, etc. Secondly, patients will have cardiovascular system manifestations, which is the most common cause of death in uremic patients. Patients often have a combination of hypertension, heart failure, arrhythmia or myocardial infarction. Patients often have a combination of hypertension, heart failure, arrhythmia or myocardial infarction. Thirdly, the patient will also show symptoms of hematological system, the most common one is anemia, the patient will feel general weakness, and often the hematocrit is usually below 100g/L. The fourth patient will have serious disorders of the internal environment, such as hyperkalemia, metabolic acidosis, and disorders of calcium and phosphorus metabolism.