Christopher Ellis describes slicing his knee on broken glass during a street-hockey accident but feeling no pain at first. He uses this to explain the biopsychosocial model: pain comes from tissue damage plus your psychological state and social context. Sleep deprivation and stress reduce your body's ability to handle pain.
I remember in high school, I was playing street hockey and I slipped on some wet leaves and I fell on a broken bottle, glass bottle. And it wasn't until everybody pointed at my knee and were like, oh, did I realize anything was wrong because I felt nothing. So the glass had sliced my knee open and the fat pad behind my kneecap was kind of sticking out. I was bleeding, but felt nothing. It was kind of crazy. So this model, the biopsychosocial model of pain, helps us understand the why behind pain. Lack of sleep puts you in a a very stressed state as is. So now your body has less adaptability, less ability to handle whatever you throw at it.
