Maybe their frustrations are unrelated, or maybe you did something to upset them but don't realize it. Understanding how your sibling feels will help prevent an argument from happening.
[header] How to stop fighting with your brother or sister [title] Put yourself in your brother or sister's shoes, if they are frustrating you. [step] Before you fight, think about why your sister may be in a bad mood. Ask yourself what you may have done to upset your brother.