Why would a fuse not reset?

Could you elaborate on the reasons why a fuse might fail to reset? Could it be due to a persistent overload or a short circuit that hasn't been resolved? Are there any specific indicators that would suggest the cause of the fuse not resetting, such as discoloration or damage to the fuse element? Additionally, is it possible that the fuse itself is faulty and needs to be replaced? Understanding the root cause of the issue would be crucial in resolving it effectively.