Bronchial asthma is a common chronic respiratory disorder in children, which belongs to the category of asthma and croup in Chinese medicine. Modern medicine considers this disease as an allergic disease, whose pathology is characterized by chronic inflammation of the airways and airway hyperresponsiveness, and proposes to use inhaled glucocorticoids as the main drug to prevent and control the attacks of this disease, which is quite effective, but the side effects are obvious and the long-term efficacy is not satisfactory. Therefore, it is important to explore the effective treatment plan of this disease from the Chinese medicine. 1. The formation and pathogenesis of wind, phlegm and stasis 1.1 Wind and asthma Wind is different from external wind and internal wind. The external wind is the external wind, which is one of the six malaise. Clinical observation shows that external wind is the primary cause of asthma and recurrent attacks in children. The external wind includes abnormal weather, foreign substances and odors, dust, pollen, mites, etc. Children’s asthma is often triggered by external wind, and the attack is preceded by aura symptoms of itchy nose, itchy eyes, nasal congestion, sneezing, runny nose and cough. In addition, asthma can be triggered by drastic changes in emotion, and the attack is characterized by vocal breathing, airway contracture, chest tightness like choking, and rapid onset and stopping, which is in line with the characteristics of wind “being good at moving and changing several times” and “moving when wind is victorious”. This suggests that wind is an important pathological factor in asthma attacks. Wind is closely related to the dysfunction of lung, spleen, liver and kidney. Among them, the lung and spleen are mainly responsible for the external wind. If the child has insufficient lung and spleen, and the child’s external guard is not strong enough, the child is susceptible to external wind. If the child feels wind or eats seafood, the evil will be embedded in the lung and spleen, leading to phlegm, and the loss of lung elevation may lead to asthma attack. The liver and kidney are mainly responsible for the formation of internal wind. Because “liver is the master of wind”, the child’s emotions and moods are out of order, depression hurts the liver, liver yang turns into wind, wood and fire punish gold, liver wind induces volatile phlegm, the lung loses publicity and lowering, wind shakes the bell and asthma attacks. As “read medical essays” said: “all diseases of gas knot …… asthma …… are liver qi can not be relaxed due to also”. In addition, the formation of internal wind is related to the kidney. The Chinese medicine believes that the kidneys are the foundation of the innate nature, sending the yin and yang inside, dominating the innate endowment, growth and development. Children with asthma are born with insufficient endowment and have an atopic constitution, which makes them prone to wind and phlegm. In the Song dynasty, Xu Shuwei stated in the “Puji’s recipe” that “there are those who suffer from this disease for life, and there are also those who pass it on from mother to child”, and in the Qing dynasty, Ye Tianshi called asthma “infantile heavenly roar” in the “Clinical Guide to Medical Cases”. Modern medicine also found that children with asthma and their families often have a history of eczema and urticaria, and some experiments have confirmed that even if children with asthma do not have clinical symptoms of kidney deficiency, their hypothalamic-pituitary-adrenal axis function is low, with potential changes of adrenal cortical insufficiency. 1.2 Phlegm and asthma From the point of view of disease mechanism, phlegm is the root of asthma, which is generally agreed by sages. For example, Zhu Danxi believes that asthma is “mainly due to phlegm”, and the book “Evidence and treatment of croup? Croup” says: “Croup is the long and frequent occurrence of phlegm and asthma, because of the congestion of gas inside, the feeling of untimely outside, and the phlegm in the diaphragm, the combination of the three, closed and rejected the airway, the fight has a sound, the development of croup.” Wang Kentang said that croup “is characterized by a lot of phlegm in the chest, which is knotted in the throat and wrestles with the qi, making a sound in the throat as it breathes”. From the point of view of clinical asthma attack characteristics, phlegm rises with qi during the attack, qi is blocked by phlegm, and phlegm and qi fight each other, resulting in a sound in the throat or phlegm sounding like roar, shortness of breath and chest tightness like suffocation, which is the result of external evil inducing phlegm. From the perspective of modern medicine, the process of asthma development is characterized by the production of a large number of inflammatory cells, inflammatory mediators, cytokines and various immunologically active cells, leading to the formation of chronic inflammation in the airways, and this process and the various substances produced in the process can be understood as the formation of “persistent phlegm” in Chinese medicine. The production of persistent phlegm is mainly related to the dysfunction of lung, spleen and kidney. The internal organs of the lungs, spleen and kidneys become dysfunctional in qi-chemistry due to external sensation of six mirths or internal injury from diet and seven emotions. The lung is responsible for declaring and lowering, regulating water channels and spreading fluid; the spleen is responsible for transporting and transforming fluid; the kidney is responsible for vaporizing fluid. Therefore, malfunction of the lungs, spleen and kidneys can lead to water metabolism disorders, stagnation of moisture in the lungs and phlegm. For example, the Nei Jing says: “The kidney is the source of phlegm, the spleen is the source of phlegm, and the lung is the reservoir of phlegm”. Another example is Chen Xiuyuan’s summary: “The origin of phlegm is water, which originates from the kidney; the movement of phlegm is dampness, which is dominated by the spleen; and the formation of phlegm is gas, which is stored in the lung”. 1.3 Blood stasis and asthma Tang Rongchuan’s “Theory of Blood Evidence” says: “The airway of a person must not be blocked, and if there is blood stasis inside, the airway is blocked and cannot be lifted and wheezed”, and also “blood stasis multiplies the lung, coughing and wheezing. Most children with asthma have different degrees of blood stasis: clinical manifestations include dark face, dark lips, blue eyes, purple claw nails, purple fingerprints, blue tongue or petechiae, purple tongue, dark and angry veins under the tongue, chest tightness and chest pain. From the blood rheological examination, it was found that the child’s blood was viscous and highly coagulable, with different degrees of microcirculatory disorders. In terms of the course of the disease, recurrent attacks, which do not heal over the years, “prolonged illness will lead to stasis”. Therefore, blood stasis is closely related to the development of asthma, and is another important factor leading to recurrent asthma attacks and difficult to cure. Chinese medicine believes that “the lung is facing all the veins” and is the master of all the qi. The normal operation of blood in the veins is closely related to the function of the lung as the master of the joints, in addition to the driving effect of the heart qi. The lung is the master of qi, and qi is the marshal of blood; if qi moves, blood moves; if qi stagnates, blood stagnates. Due to the recurrent asthma attacks, the airway is contracted and the lung qi is not properly declaring and descending. The blood stasis in the lung lobe for a long time obstructs the qi flow and affects the normal transmission of fluid, which leads to stagnation of fluid and phlegm, and phlegm in the lung becomes croup when touched by external evil. To sum up, in the whole course of asthma, wind, phlegm and stasis are both pathological products and causative factors of the disease. In terms of the relationship between the three, phlegm can breed phlegm, stasis can cause phlegm, wind can cause recurrent attacks of asthma and aggravate phlegm and stasis, and phlegm and stasis can cause wind to have opportunities to take advantage of each other, and the three can mutually transform and generate each other, causing a vicious circle, which becomes an important pathological factor for the chronic persistence of asthma. Therefore, in the treatment of asthma, interventions targeting wind, phlegm and stasis should be carried out throughout. 2. Treatment from wind, phlegm and stasis 2.1 Treatment of wind There is a difference between dispersing the external wind and quenching the internal wind. If the external wind attacks the lung, the evil is in the upper jiao, the external wind and cold are felt, and the phlegm and phlegm are in the lung, the treatment should be to dispel the wind and cold, resolve the phlegm and calm the asthma. In mild cases, add or subtract three woose-tang, and in severe cases, add or subtract eucommia-ephedra-tang. In cases of external wind and internal phlegm-heat, the treatment should be to clear heat and promote lung circulation, resolve phlegm and relieve asthma, with addition and subtraction of Ma Heng Shi Gan Tang in mild cases and addition and subtraction of Ding Qi Tang in severe cases. In the case of combined allergic rhinitis with symptoms such as nasal itching and sneezing, add Xin Yi, Cang Er Zi, and Hesperidin; in the case of combined allergic dermatitis with itchy skin, add Dizi Zi, Bai Xian Pi, Xu Changqing, and Bitter Ginseng; in the case of combined throat discomfort, add Cicada Jiao and Sclerotium; if the wind moves the airway contracture is more acute, use Dry Di Long, Sclerotium, and Hooked Vine; in the case of more acute, use Roasted Centipede and Roasted Scorpion to increase the power of extinguishing wind and relieving spasm and urgency. If the wind roaring is prolonged and the contracture of the airway continues to be difficult to be calmed down, white peony, hooked vine, wu wei zi and licorice can be added as appropriate to calm the liver and slow down the urgency of the lung. 2.2 Treating phlegm The principle of treating phlegm in asthma is to remove the tangible phlegm to benefit the lung qi when the attack occurs and to cut off the root of croup by eliminating the invisible phlegm in normal times. The methods of removing tangible phlegm during asthma attack include warming cold phlegm, clearing hot phlegm, drying damp phlegm and removing stubborn phlegm. For cold asthma and phlegm congestion, with high chest and full breath, thin white sputum, white slippery tongue coating, cold form and cold limbs, almonds, scape seeds, soursop, white mustard seeds, lycopodium, ginger and whirling flowers can be used to warm cold phlegm; for hot asthma and phlegm congestion, with high chest and shortness of breath, thick yellow sputum, hot body and red face, abdominal distension and constipation, and thick yellow tongue coating, bile and nancellus star, azure yellow, orange red, zhebei mother, guadua peel, loquat leaf, scutellaria and fishy grass can be used to clear hot phlegm; for phlegm and dampness congestion For wheezing and chest congestion, with white phlegm and greasy coating, we can use Fuxianxia, Nanxing, Chenpi, Poria, Radix Platycodon, Citrus aurantium to dry dampness and resolve phlegm; for recurrent coughing and wheezing, chest congestion, thick and agglutinated phlegm, and unpleasant coughing and vomiting, we can use Saponaria, Pores, Sea Fushi, Sea Clam Shell, Gooseberry to clean up stubborn phlegm. During the remission period of asthma, we should focus on tonifying the lung, strengthening the spleen and benefiting the kidney, so that the lung health is solid, the spleen is healthy and the kidney is full of qi, so that there is no source of phlegm and the purpose of asthma prevention is achieved. 2.3 Treatment of blood stasis The Treatise on Blood Evidence points out: “It is important to know that the congestion of phlegm and water is caused by blood stasis, but removing the blood stasis will make the phlegm and water disappear.” Therefore, in asthma treatment, early detection of the signs of blood stasis and flexible use of blood activating drugs can not only improve pulmonary circulation, promote blood flow, eliminate bronchial mucous membrane edema, reduce obstruction, play a good role in calming asthma and prevent the continuation and transformation of the disease, but also enable the circulation of qi and blood and the regulation of dirty qi in the remission period, thus effectively preventing recurrent attacks. In the treatment of asthma stasis, it is advisable to use drugs to clear the stasis during the exacerbation period, and to use drugs to tonic the stasis during the remission period. At the beginning of the disease, we can use Tiger Balm, Yujin, Chuanxiong, and Xiangxiang alone, while at the end of the disease, we can use the above mentioned drugs in combination or add Angelica Sinensis, Tao Ren, Safflower, Salviae Miltiorrhizae, Liu Zhonu, or in extreme cases, we can add Trigonella, Curcumae, and Stinging Worm to break blood and remove stasis. In addition, the treatment of blood stasis should not forget to regulate qi, and can add green peel, Chen Pi, Citrus aurantium shells, etc., which can make “qi flow, blood flow”. 3. Case example Xu, male, 7 years old. He has been diagnosed with asthma since he was 3 years old and has several attacks every year. At the time of consultation, he had been coughing and asthma for 7 days, which had slightly improved with western medical treatment, but he was still unable to sleep every night. The cough was accompanied by coughing and sputum, white and foamy, shortness of breath and chest tightness, a pale white face, a pale tongue with white greasy coating, morning nasal congestion and sneezing, and a floating and tight pulse. Physical examination: widened rib space, thickened breath sounds and scattered croup in both lungs. Pulmonary function tests showed moderate to severe airway obstruction. The diagnosis was bronchial asthma (exacerbation phase). The evidence belongs to external wind-cold and phlegm-drinking in the lung. The treatment is to dispel wind and cold, calm asthma and relieve cough.