COUGH and COUGHING Coughing is the bodys mechanism to clear the lungs and/or throat. Coughs are caused for two main reasons, something is irritating the throat or something is irritating the lung tubes. Many coughs are cause by post nasal drainage that accompany upper respiratory infections. The mucous drains from your nasal area down the back of your throat and irritates the area causing cough and sore throat. For this problem, antihistamines such as benadryl work very well because they stop the drainage. With irritation in the lungs such as from pneumonia or bronchitis(asthma) the cough is an attempt to remove the mucous plugs from the bronchioles and bronchus. Narcotic antitussive remedies block the nerve receptors in the throat area, thus they stop the message that irritation is occuring in the throat. People with bronchitis may find that bronchodialators such as albuterol work very well in preventing cough.