Yes, using "yourself" indicates that YOU are the one injuring/hurting yourself (as in you are inflicting pain on your own body). English always uses "myself" "yourself" "ourselves" "oneself" to refer to my/your/our/one's body. Hopefully that helps!

Hurt is usually used with an object - either saying that something is in pain or that something was injured. By saying you hurt yourself, you mean that you did something that caused an injury to yourself. If you leave out "yourself",it just means that you are in some kind of general pain.