It is important to note that there are various types of bipolar disorder:
As seen on WebMD,
A person affected by bipolar I disorder has had at least one manic episode in his or her life. A manic episode is a period of abnormally elevated mood, accompanied by abnormal behavior that disrupts life. Bipolar I is typically seen as the more severe type due to the extreme highs and lows present.
Bipolar II is similar to bipolar I disorder, with moods cycling between high and low over time. However, in bipolar II disorder, the “up” moods never reach full-on mania.
In rapid cycling, a person with bipolar disorder experiences four or more episodes of mania or depression in one year. About 10% to 20% of people with bipolar disorder have rapid cycling. Rapid cycling is also significantly more common in women than men.
In most forms of bipolar disorder, moods alternate between elevated and depressed over time. But with mixed bipolar disorder, a person experiences both mania and depression simultaneously or in rapid sequence.
Cyclothymia (cyclothymic disorder) is a relatively mild mood disorder. People with cyclothymic disorder have milder symptoms than in full-blown bipolar disorder.