This subject got me curious so I read up on dueling. Apparently in the sword era most duels were to "first blood" not to the death, and even after pistols became the preferred weapon the object wasn't to kill an opponent or even to win. It was more important to demonstrate courage by showing up. Both parties upheld their honor simply by going through with it. Most deaths that occurred were from infections, not from the wound itself being fatal. It was also common and acceptable to try to avoid a duel through negotiation or an apology.

What OP meant by petty disagreements is unclear, but duel challenges were often made over matters of honor. Some of the issues might seem petty to us today, but in the dueling community reputation and image were vital social currency. For a rough comparison consider modern celebrities losing fans and jobs because of bad tweets (or even for liking the wrong tweet).