<prompt> Common cause of congenital stridor in child-LaiyngomalaciaLaryngeal webHemangiomaSubglottic stenosis  <response>: Ans. is a i.e., Laryngomalacia STRIDORo Due to upper airway obstruction, o Types -Inspiratory stridor - Obstruction above vocal cords supraglottic.Expiratory stridor - Obstriction distal trachea.Diphasic - From supraglottic or proximal tracheal.Causeso Infective:Croup lanyngo tracheo bronchitisBacterial trachetisRetropharyngeal abscess o Congenital:Laryngumalacia: 60 of all total most common cause.Vocal cord paralysis - 2nd most common.Subglottic stenosis - 3rd most common.o Iatrogenic : Long term intubation leads to subglottic stenosis - most common causes of aquired stridor in children,o Neoplasm : Recurrent respiratory papilloma RRP MC benign tumor and laynx. 