Perspective on the human cough reflex

Persistent cough is one of the most common medical complaints that impacts the quality of life and is responsible for a significant proportion of annual ambulatory medical visits and medical expenses in the United States [1]. Involvement of the upper and/or lower airways play pathogenetic roles in cough development and the association of allergy represent an important contributing factor for cough exacerbation. This perspective explores the complexity of coughing and suggests hypotheses about the unique evolutionary basis for the human cough reflex.Considering a casual connotation, coughing is a reflex-evoked modification of normal breathing patterns [2]. More explicitly, the cough reflex is a multifaceted, precisely timed, neuromuscular phenomenon characterized by the precise concurrent and sequential coordination of the activation patterns of the diaphragm, various muscle groups of the chest wall, cervical muscles, abdominal muscles, laryngeal abductor and adductor muscles, medullary and higher cortical regions of the brain [3,4]. The complexity of coughing is espoused by television personality Jerry Seinfeld when he informs his friend George Costanza (played by Jason Alexander): "When you cough there are thousands of unseen muscles that suddenly spring into action. It's like watching that fat guy catch a cannonball in his stomach in slow motion" (from The Apology, the 165th episode of the NBC sitcom Seinfeld that was first aired on December 11, 1997).Accordingly, I am attending a dinner with my wife and observe her walking across the room towards me. As she does so, she aspirates a sliver of ice from a glass of beverage she is drinking. My wife stops walking and her eye brows arch. She informs me later that at that instance she experienced the sensation of an urge to cough. She deftly places a clenched fist to her mouth as her face reddens; her eyes water, narrow and then tighten. Her chin lifts to some extent as her head rears back; perspiration appears on her u