When it's hard to breathe, maybe pain doesn't matter. Focus on "Dyspnea as a noxious sensation: inspiratory threshold loading may trigger diffuse noxious inhibitory controls in humans".
Banzett
Robert B
RB
Gracely
Richard H
RH
Lansing
Robert W
RW
D004417:Dyspnea / Q000503:physiopathology* / Q000523:psychology*; D006801:Humans; D009619:Nociceptors / Q000502:physiology; D010146:Pain / Q000503:physiopathology*; D015656:Respiratory Mechanics / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology