A chess match is intended to measure your chess ability, not the state of your health or your balance.
If you get injured, you must still play your games. If you can't play, you lose by forfeit.
Some matches (world championships, for example) are played under rules that allow each player a few days postponement if they submit a note from the team doctor. Ordinary tournaments have no such provision, though.
So, I've heard about people getting ill/injured during a match or tourney, but how do the TD's handle it? What happens if the player has to leave the game? If someone gets injured, let's say tripping over a chair, how do the tournament staff react? I know I've already asked about fainting and earthquakes, and may sound repetitive, but I am genuinely asking a question. And no, I'm not trying to cheat my way out of one or try to draw a game when I'm losing. (Why would I do that, I've only ever been in one tournament?) I want serious answers and would appreciate no joking around.