Keep in mind that the apostrophe means two words are connected to each other. (It's = It is)
"It's hurt" would be saying "It is hurt." Which would indicate something or someone is in pain. This term is not used much.
"It's hurt because it was kicked by a child." (This sentence describing something with an unknown gender, could be a bug)
It hurts would be saying that you are in pain.
"It hurts to say goodbye."