Cyclothymia, a psychiatric disorder characterized by emotional instability, can also be referred to as cyclothymic disorder. It is a mood disorder that falls in between bipolar disorder and major depressive disorder. Some alternative or related terms for cyclothymia include cycloid personality, cyclothymic temperament, and hyperthymic personality. Conditions that share some similarities with cyclothymia include dysthymia, which is a persistent mild depression, and borderline personality disorder, which also involves mood instability. Understanding the different terms used to describe cyclothymia can help individuals with this condition better understand their diagnosis and seek appropriate treatment.