A cough is the sudden expulsion of air from the lungs in order to clear the air passages. It is a common symptom of respiratory infections such as colds, flu, bronchitis, and pneumonia. A sore throat is medically known as pharyngitis and, as with a cough, it is a symptom. A sore throat is usually caused by a bacterial or viral infection. It can also be caused by smoking, drinking alcohol, polluted air, and allergies. Treatment options include prescription and over the counter medications, humidifiers, homoeopathy, herbal remedies, fluid therapy, nutritional supplements, acupuncture, and quitting smoking.