Many people in families become upset with each other over small problems.

许多家庭成员之间因为一些小问题彼此不愉快。

If they then go to an experienced doctor who tells them that they've been bitten by a centipede , they can then become upset and the pain will flare up.

假如他们接着去看一位有经验的医生，医生说是给百足虫咬伤了，那个痛马上就发作起来。