The oxygen saturation of the elderly is 95%-100%. The oxygen protection degree is the percentage of oxygen combined with hemoglobin in the blood, with all the hemoglobin, if the oxygen saturation is less than 90%, it is mostly considered to be caused by the problem of lack of oxygen in the body, and can appear the symptoms of chest tightness and shortness of breath, and the cyanosis of the skin can appear when the oxygen saturation is less than 60%, and the symptoms of cardiovascular and cerebrovascular hypoxia, and the appearance of Breathing difficulty, wheezing, dizziness, headache, weakness and other symptoms, and even shock can occur. It is recommended to find the cause in time for active treatment. If it is caused by acute heart failure, ventilator assistance is needed in time, and diuretic, cardiotonic and vasodilator drugs should be applied to deal with it.