Blood oxygen is usually above 95%, if the blood oxygen is 85% consider the existence of hypoxia or even respiratory failure, it is dangerous. If the blood oxygen reaches 85, it may affect the normal exchange of blood oxygen, and may gradually appear dyspnea, dizziness, headache, body weakness and other symptoms, and even gradually appear hypoxia, which will have a certain impact on the patient’s life and safety. Once the blood oxygen 85 consider the existence of respiratory failure may be, it is recommended to go to the hospital in a timely manner to seek medical treatment, can first take the mask oxygen for auxiliary treatment to improve the symptoms of the purpose, but also need to improve the blood gas analysis, lung CT and other tests to clarify the cause of the disease and then targeted treatment. In addition, we should maintain a good diet and rest habits, combined with their own physical exercise, after meals to appropriate walking.