The difference between Suicidality and Self Injury is INTENT. 

Individuals engage in self-harm to feel “something” other than numb or empty. Sometimes self-harm can be a way to signal to others that they need help or the harming behavior has become a maladaptive coping skill. Individuals who express suicidality are experiencing hopelessness, despair, and thinking that the end of their life could be the solution to their problems. Although both conditions can stem from similar situations or contexts, self-harm does not always indicate that the individual wants to end their life.  Learn More...