Bronchial asthma (AD) is a chronic inflammatory disease of the respiratory system, characterized by bronchial hyperreactivity, partially or completely reversible (spontaneously or due to treatment) bronchial obstruction resulting from bronchospasm, as well as mucus hypersecretion and swelling of the bronchial mucosa. AD is clinically manifested by wheezing in the lungs, coughing, shortness of breath, and signs of suffocation. Over the past few decades, there has been an increase in the number of patients with asthma worldwide. By 2006, this number was more than 300 million people. In different countries, the prevalence of AD in a population varies from 1 to 18%. In Russia, this indicator is 5.6-7.3% in the population, and in children – 5.6-12.1%. The number of patients with AD in combination with other allergic diseases, in particular AR, is increasing. To date, a unified classification has not been developed. There are classification options according to the International Nomenclature. Since 2006, most countries have used classification based on the recommendations of the Global Initiative to Combat AD [GINA, 2006]. • Allergic: – atopic (due to the development of IgE-dependent reactions); – non-atopic (as a result of non-IgE-dependent reactions; – including infectious-allergic). • Non-allergic (characterized by the absence of allergic reactions in the pathogenesis of BA (including aspirin BA). • Mixed (several mechanisms are involved in the pathogenesis). Several types of B. are distinguished by their severity. • Mild intermittent BA – symptoms of the disease occur less often than once week, nocturnal symptoms – no more than twice a month. FEV1 or peak expiratory flow rate is more than 80% of the norm (variability of indicators less than 20%). • Light persistent AD – symptoms occur more than once a week, affect physical activity sleep and sleep. Nocturnal symptoms occur more than twice a month. FEV and peak expiratory flow rate are 80% of the norm (variability of 20-30%). • Moderate persistent AD – symptoms are daily, exacerbations affect physical activity and sleep. seizures occur more often than once a week. Patients are forced to take short-acting p2-adrenoreceptor agonists daily. FEV2 and peak expiratory flow rate are 60-80% of the norm (variability of more than 30%). • Severe persistent AD – asthma symptoms occur daily, both during the day and at night. Physical activity is limited. FEVx and peak expiratory flow rate are less than 60% of the proper values. According to the phase of the course of bronchial asthma, there are: • exacerbation (patients with any degree of severity of AD can have a mild, moderate and severe exacerbation); • remission. The degree of control distinguishes: • controlled BA; • partially controlled BA; • uncontrolled BA.