What is bipolar NOS?
Bipolar disorder is a mood disorder in which people experiences symptoms of depression that alternate with periods of increased energy. Note that mood elevation is not necessary to be in a high. Many people feel anxious, agitated, irritable, and restless during these periods of highs.
Muffy Walker
Mental Health Nursing
Bipolar Disorder is a condition which includes fluctuation of moods from a "high" or irritable mood to depression. The "mood swings" between mania and depression can be very quick or last long period of times. Some people cycle rapidly between the two. 
Dr. Michael Roizen, MD
Internal Medicine

NOS is a regulatory phrase used to ensure that doctors are treating things and billing for things “by the book.” NOS means Not Otherwise Specified. Huh? Let’s start at the beginning.


Bipolar disorder is a treatable mental illness that causes extreme mood swings. There are four types in official lingo: I, II, NOS (Not Otherwise Specified), and cyclothymia. The NOS type refers to symptoms that do not meet the criteria for bipolar I or II. The symptoms are intense and represent an obvious change from your normal mood and behavior, but they may not last long enough or you may not have enough of them to qualify as bipolar I or II.


Talk to your doctor about any symptoms you are having that represent a change in mood or behavior.

Continue Learning about Bipolar Disorder

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.