Stupor is a state of near-unconsciousness where someone seems awake but can barely think, move, or respond to what's happening around them. Imagine being so exhausted after staying up all night that you sit staring at nothing, unable to process what people are saying to you. That foggy, detached feeling can resemble stupor, though true stupor is much more extreme.

Stupor can result from severe illness, extremely high fever, or serious injury. Someone in a stupor might have their eyes open but won't react normally when you speak to them or touch them. They might mumble incoherently or move very slowly, as if their brain and body have almost completely shut down. Doctors treating a patient in a stupor work urgently to find the cause, since stupor signals that something is seriously wrong.