High or low blood concentration is not very good. Normally, the saturation of human arterial blood oxygen is between 95% and 99%, and the oxygen concentration of venous blood is at 75%. Need to refer to the arterial blood blood sample results, the high concentration indicates that the body’s metabolism will be better, after too high will also lead to excessive aging of cells. If it is too low, it means that the inhaled oxygen will be less, which will easily cause the symptoms of difficulty in breathing and chest tightness. Low blood oxygen can also lead to mental fatigue and lack of strength, and also increase the prevalence of emphysema, which can easily lead to chest tightness, shortness of breath and coughing. It is necessary to make a correct diagnosis according to other examination results and clinical manifestations, and treat with medications under the guidance of doctors.