It's not him not recognizing her that's unsettling, or even the gory cough. It's the lack of jokes and sense of graveyard humor. Something is really wrong here. Wade was already to crack a joke about his cancer cells, but he was just about as quick to heal. This is not good.

"You don't recognize me? How long have you been coughing up blood?" Look important questions come quickly enough, and she's posed to catch him if he starts to fall. He was there for her not that long ago, after all.