Burden

: someone or something that is very difficult to accept, do, or deal with.

Having a chronic illness was a huge burden, on themself and others.

Gas-leak

Used to describe a reactive person as though they are similar to an actual gas leak in the way that even the smallest spark can set them off into a raging flame.

"Why do avoid people when you think they're frustrated?"
"Not really sure, but it's probably because growing up my mother was a real gas-leak."