Acne is caused by the following mechanisms in Chinese medicine: (1) Heat in the lungs and stomach: Most often seen in adolescents, the patient’s body is full of Yang heat. If the patient feels external evil, poison and heat will fight with each other, and the heat will go up through the meridians and blood will travel with the heat and congest on the chest. 2. Stagnation of Qi and Blood: Most often seen in women. It is caused by blood-heat and heat in the lung and stomach, which causes blood-heat congestion; or depression due to emotion, loss of qi flow, and stagnation of qi and blood; or menstrual blood is not regulated due to the arrival of Tiankui, which is depressed and cannot travel smoothly. The result is poor circulation of qi and blood in the lung and stomach meridians, stagnation of the skin, stagnation of nodules, and difficulty in dissipation. 3, blood stasis and phlegm knot: mostly seen in men, the disease process for a long time, the lung and stomach accumulated heat is not resolved, refining damp into phlegm, blocking the meridians, so that the meridians are not smooth qi and blood stagnation, phlegm and blood knot, knot does not disperse. In conclusion, the root of the disease is the heat of the Yang body, and the condition is caused by poor diet and external attack; the blood stasis and phlegm knot make the disease complicated and serious.