Pale blue face or black face, mostly for real cold evidence, severe pain. Cold is the main attraction, and its nature is Yin condensation, cold condensation and Qi stagnation, menstrual vessels are constricted, blood flow is not smooth, stasis color is exposed, so the blue color is seen. Severe pain, resulting in constriction of the meridians and poor blood flow, can also be seen as cyan. Patients with blue-gray face are mostly suffering from poor blood flow, which can be seen in patients with various cardiovascular diseases, lung diseases, and also in patients with chronic poisoning. Individual symptoms are not clinically significant and need to be diagnosed based on other accompanying symptoms. According to Chinese medicine, patients with blue-gray face, blue lips, and painful suffocation of the heart and chest are often seen in patients with chest paralysis, mostly due to deficiency of heart qi or deficiency of heart yang, weak propulsion, and slow blood flow, resulting in stasis of heart veins. If the patient has palpitations, recurrent chest pain, sudden onset of severe chest pain, blue-gray face, blue lips, cold limbs and weak pulse, it is a heart yang storm off evidence. Sweating and weakness, palpitation and shortness of breath, aggravated by movement, coughing and wheezing, blue and gray face, pale tongue, thin white fur, sunken and weak pulse. This evidence is caused by a prolonged illness, gradual loss of vital energy and injury to both heart and lung. Heart Qi is deficient and blood vessels are not smooth, hence the palpitations and greenish-gray complexion. Deficiency of lung qi, loss of purification, hence shortness of breath and shortness of breath. In addition to direct diagnosis based on the above symptoms, patients with cyanosis are also clinically diagnosed with skin smear microscopy, skin color, electrocardiogram and other tests to confirm the diagnosis of cyanosis caused by certain parts of the body.