Suicidal ideation is a common medical term for thoughts about suicide, which may be as detailed as a formulated plan, without the suicidal act itself. Although most people who undergo suicidal ideation do not commit suicide, some go on to make suicide attempts. The range of suicidal ideation varies greatly from fleeting to detailed planning, role playing and unsuccessful attempts, which may be deliberately constructed to fail or be discovered or may be fully intended to succeed.

In a study conducted in Finland, 22% of the suicides examined had discussed suicidal intent with a health care professional in their last office visit.