People tend to think of Bipolar I as being "worse" than Bipolar II. In discussions about this, people diagnosed with Bipolar I have sometimes said, "I wish I only had Bipolar II."
I'm not here to tell you people with BP I don't have a rough time - they do. But what those who said they wished they had BP II, and the public in general, don't realize is that Bipolar II is profoundly different from Bipolar I.
If you have ever had soaring mania, perhaps with hallucinations or delusions; if your mania has ever been so out of control that you had to be hospitalized; indeed, if you've ever had a manic episode at all, you have Bipolar I Disorder. Mania and the hypomania of Bipolar II and Cyclothymia (also known as Bipolar III) share some characteristics, but the severity of mania makes a great deal of difference. (See Mania vs. Hypomania.)
But people who have Bipolar II have a miserable time at the opposite pole: depression. In general, these people have far more depressive than hypomanic episodes. Those depressive episodes last longer and are more frequent than in people with BP I. Again, this isn't to say that people with BP I can't have very bad depressive episodes. They just aren't likely to have them as frequently, or for as long as, people with BP II.
And there is one more key difference between the two disorders - the one that sometimes makes me wish I had Bipolar I, believe it or not. That is the fact that people with BP II are very likely to feel at least slightly depressed almost all the time that they aren't hypomanic.
It's true for me. In fact, my psychiatrist told me that on the 1-10 scale he uses for rating mood, 6 is normal, and most of his patients with BP II hardly ever get above 5 (having to push yourself some), and 4 (having to push yourself often) is more common.
That's where I live most of the time - between 4 and 5, with days I'd rate as 3 at least twice a week. And at those levels, my symptoms don't even qualify as a diagnosable depressive episode! Yet I'm struggling all the time to a greater or lesser degree. "Up" periods generally don't last for more than a few hours.
So don't let anybody tell you that because you have Bipolar II Disorder you "aren't that sick." Both Bipolar I and Bipolar II are serious disorders. It's just important to understand that they are so different that they can't be compared.
Mantere, O., et al. (2008). Differences in outcome of dsm-iv bipolar i and ii disorders. Bipolar Disorders, 10(3), 413-25. Abstract retrieved from http://www.ncbi.nlm.nih.gov/pubmed/18402629
Maina, G., et al. (2007). Health-related quality of life in euthymic bipolar disorder patients: differences between bipolar i and ii subtypes. Journal of Clinical Psychiatry, 68(2), 207-12. Abstract retrieved from http://www.ncbi.nlm.nih.gov/pubmed/17335318