The causes of bluish color are complex, and the common causes include hysteria, heart disease, respiratory disease and so on. 1. Hysteria: Hysteria may cause hyperventilation, making the patient appear blue and other manifestations. 2. Heart disease: bluish face may also be suffering from heart disease, such as heart failure, causing pulmonary stasis, resulting in a decrease in blood oxygen saturation, which leads to the phenomenon of bluish face. 3. Respiratory diseases: this may also be one of the causes of cyanosis, such as chronic obstructive pulmonary disease, chronic bronchitis and other diseases, will cause a decrease in blood oxygen saturation, resulting in the appearance of cyanosis. These are only some of the common causes. If you have a bluish color, you need to pay attention to it, and it is recommended to improve the relevant examinations under the guidance of the doctor, to clarify the cause of the disease so as to treat it systematically.