Difficulty in breathing occurs when coughing for a number of reasons: 1. Coughing is often caused by bronchial constriction. If the bronchi become violently constricted, it will cause ventilation problems and cause difficulty in breathing. 2. Coughing is often caused by inflammation, as there is inflammatory exudate, or phlegm, in the bronchi and alveoli, which can block the alveoli and bronchi and cause difficulty in breathing. 3. Coughing can also be caused by pharyngitis, an inflammation of the throat that causes edema and congestion in the throat. If the edema and congestion are serious, they can block the airway and cause breathing difficulties. It is best to treat with nebulized inhaled glucocorticoids and bronchodilators, such as nebulized inhaled budesonide and terbutaline. If there is inflammation, you also need to use anti-inflammatory drugs, such as busulfan anti-inflammatory oral solution.