Generally there are 3 kinds: bipolar i, bipolar ii and bipolar nos.
The difference depends on the symptoms of mania (severe insomnia
, extreme energy, racing thoughts, pressured speech, elated and/or irritable moods). In bipolar i the mania lasts 3-4 days or is severe enough to need hospital stay. In ii the mania is called hypomania
and is of shorter duration. In nos not all symptoms of mania exist.