The causes of cyanosis around the lips and mouth are as follows: 1, the main consideration of heart or lung lesions, such as coronary heart disease, angina pectoris, myocardial infarction, coronary artery stenosis, atheromatous plaque formation, due to the lack of blood supply to the heart, there is often peripheral cyanosis, and therefore can be manifested as cyanosis around the lips and mouth; 2, respiratory diseases, such as severe pneumonia, pulmonary infarction, and other diseases, due to the dysfunction of the ventilation can also occur around the lips and mouth Cyanosis around the mouth and lips; 3, if the newborn appears to have cyanosis around the mouth and lips, we should be alert to the appearance of congenital heart disease. Once the patients appear perioral cyanosis, we should carry out active diagnosis and treatment, such as through the electrocardiogram, cardiac ultrasound, blood oxygen saturation monitoring, to clarify the causes of cyanosis, the use of oxygen inhalation to improve the blood supply of the heart, improve pulmonary ventilation function and other means of treatment to alleviate the patient’s symptoms.