ng osp as ms , ▁whether ▁aw ake ▁or ▁as leep . ▁In ▁an ▁ear , ▁nose , ▁and ▁thro at ▁practice , ▁it ▁is ▁typically ▁seen ▁in ▁people ▁who ▁have ▁silent ▁re fl ux ▁disease . ▁It ▁is ▁also ▁a ▁well ▁known , ▁inf re quent , ▁but ▁serious ▁peri oper ative ▁comp lication . ▁ ▁It ▁is ▁likely ▁that ▁more ▁than ▁ 1 0 % ▁of ▁d rown ings ▁involve ▁l ary ng osp asm , ▁but ▁the ▁evidence ▁suggests ▁that ▁it ▁is ▁not ▁usually ▁effective ▁at ▁prevent ing ▁water ▁from ▁entering ▁the ▁tra che a . ▁ ▁Sign s ▁and ▁sympt oms ▁ ▁The ▁main ▁sympt om ▁is ▁ch oking ▁and ▁difficulty ▁or ▁in ability ▁to ▁bre at he ▁or ▁speak , ▁a ▁feeling ▁of ▁suff ocation , ▁which ▁may ▁be ▁followed ▁by ▁hy po x ia - indu ced ▁loss ▁of ▁conscious ness . ▁As ▁the ▁air way ▁re opens , ▁breath ing ▁may ▁cause ▁a ▁high - p itch ed ▁sound ▁called ▁str idor . ▁The ▁episode ▁s eld om ▁last s ▁over ▁a ▁couple ▁of ▁minutes ▁before ▁breath ing ▁is ▁back ▁to ▁normal . ▁ ▁C aus es ▁Vari ous ▁stim uli ▁including ▁ast h ma , ▁all erg ies , ▁exercise , ▁stress , ▁and ▁ir rit ants ▁such ▁as ▁smoke , ▁dust , ▁f umes , ▁liqu ids , ▁and ▁food ▁can ▁trigger ▁l ary ng osp asm . ▁It ▁is ▁common ▁in ▁d row ning , ▁both ▁as ▁a ▁direct ▁response ▁to ▁in hal