How can we measure sympathetic nervous system "tone" in patients?
D001342:Autonomic Nervous System Diseases / Q000097:blood / Q000503:physiopathology; D006801:Humans; D009638:Norepinephrine / Q000097:blood*; D013564:Sympathetic Nervous System / Q000502:physiology* / Q000503:physiopathology
D009638:Norepinephrine