Should I use signed or unsigned variables for HP and money?

Technically, they should be unsigned, since they shouldn't be negative, however, I've seen lots of games use signed variables so I'm curious.

I know that using signed variables for HP is easier, but is that the only reason?

example if hp is unsigned: c if (enemy.dmg > player.hp) die(); player.hp -= enemy.dmg

example if hp is signed: c player.hp -= enemy.dmg if (player.hp < 0) die();

I also wonder if it has something to do with the fact that signed variables are the default type in all programming languages.