الفهرس 
Introduction and aim of the workOnly 14 pages are availabe for public view
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Abstract
Asthma is a common disorder whose prevalence in the population estimated to range from 3% to 50/0. Bronchial asthma is an inflammatory airway disease associated with intermittent respiratory symptoms, bronchial hyperresponsiveness and reversible airway obstruction and is phenotypically heterogeneous. The airflow obstruction of asthma is due to combination of bronchial smooth muscle qontraction, mucosal edema and inflammation, and viscid mucus secretion. These pathophysiologic events cause asthma as they lead to reduction in small airway diameter and increase in airway resistance which make it difficult for inspired air to escape the lungs. These changes lead to reduction in forced expiratory volumes and flow rate, and hyperinflation of lung with air trapping. The increase in the work of breathing creates a sense of breathlessness.