It occurs when the muscles of the soft palate at the base of the tongue and the uvula (the small fleshy piece of tissue hanging back of the throat) relax, partially blocking the opening of the airway.

• 当它发生在舌根部的肌肉的软腭和悬雍垂（小片组织肉挂在喉咙后面）放宽，部分阻塞气道开放。