The cough reflex is a protective mechanism of the airway; it avoids bronchoaspiration and its complications and, when it is altered, it can appear as a hypersensitivity syndrome; cough per se is the most common symptom for which medical consultation is sought. Chronic cough represents a public health problem with a high degree of morbidity; It represents a syndrome by itself, regardless of the underlying condition. Recent evidence suggests an abnormal and altered neurophysiologic process. Recent literature and new therapeutic mechanisms were reviewed. We are in the process of understanding the cough syndrome.