Bipolar disorder (BD) is a serious mental health condition that is relatively uncommon in adolescents. Because of its varied presentations, BD can sometimes be difficult to distinguish from typical adolescent development or attention-deficit/hyperactivity disorder (ADHD.) Understanding these varied presentations can be helpful in determining when concerns for bipolar disorder are warranted. Key points in differentiating BD from typical development or ADHD lie in its episodic nature and the severity of symptoms. Effective treatments for BD exist, and teens should be evaluated promptly when concerns are identified so that treatment can be started early.