A cough (Latin: tussis), in medicine, 's a sudden and often repetitively occurring defense reflex which helps to clear the large breathing passages from excess secretions, irritants, foreign particles and microbes. The cough reflex consists of three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound. Coughing can happen voluntarily as well as involuntarily,… (More on Coughing)