Bronchial asthma, commonly known as asthma, is mainly a chronic airway inflammatory disease involving various inflammatory cells and their components. This condition causes the bronchi to narrow and spasm, hindering the passage of air through the airways into the alveoli. Since bronchial asthma primarily affects the smaller bronchi, expiratory wheezes or stridor can often be heard upon auscultation of the trachea. In severe cases, no sounds may be heard from the patient's lungs, a condition referred to as "silent lung," which is an indication of a serious progression of the disease.