For people experiencing exploding head syndrome, the noise can feel completely real. Exploding head syndrome, also known as episodic cranial sensory shocks, is a type of parasomnia that occurs during transitions between wakefulness and sleep. Researchers have yet to determine exactly why these episodes occur, leaving the condition poorly understood despite its dramatic name. The uncertainty surrounding its causes is part of what makes exploding head syndrome difficult to study. There is no single treatment specifically approved for exploding head syndrome.