You get diagnosed, usually without you having any idea it's coming.

For me, I didn't get diagnosed until this year, and I'm 32. It gets worse as you get older.

It took one hospitalization and a treatment center for me to get properly treated.

Bipolar used to be called manic depression, because it is characterized by two main phases:

Depression: Usually more severe than even Major Depressive Disorder in bipolars. High risk of suicide. Suicidal ideation, inability to eat, complete loss of functioning, etc.

Mania or Hypomania: Periods of highly elevated mood. May exhibit grandisoity, visions, hallucinations, increase in spending and sexual activity. Increase in irritability.

There's mixed states too, like a wired depression that is lethal. They're not as common.

The #1 symptom of all mood disorders is sleep disturbance.