Black lips can be divided into two types: physiological phenomenon and pathological manifestations. Physiological black lips are related to many factors, such as genetic inheritance, living habits, dietary structure, etc. For this type of symptom, there is no obvious discomfort, except for the appearance of black lips. For this type of symptoms, in addition to the appearance of black lips, no other obvious discomfort symptoms. Cardiovascular disease is a common cause of pathologic darkening of the lips, such as viral myocarditis, hypertrophic cardiomyopathy, pulmonary heart disease and so on. Because the cardiovascular system after pathological changes, will cause the body surface tissues have insufficient blood oxygen supply, blood circulation metabolism slow down phenomenon, the lips area in the blood capillary tissue flow is not smooth, and ultimately can cause black lips, numbness, cold and other symptoms. In addition, most of the patients with this kind of disease will also be accompanied by chest tightness, chest pain, shortness of breath and other concomitant symptoms. However, the appearance of black lips does not exclude the possibility of patients with other systemic diseases, such as cirrhosis, metabolic acidosis, chronic nephritis syndrome and so on.