Why do anime characters endure so much in fights, but as soon as they are not fighting and a cat scratches them (for example) they get hurt and feel pain?

That doesn't make sense. When they're not fighting, they suddenly feel pain or bleeding from the smallest things (like a slap or a light blow to the head), but in fights, they can withstand the strongest blows.

Tips?

Hello, I wanted to ask what you do when you urgently need to go to the bathroom, but you can't right now. How do you do it, or do you have any tips? It works for men and women, girls and boys. I'm asking this in general. I'd be happy to help with age.