Bipolar illness is also known as manic-depressive illness. This is the disorder that involves incidents of serous depression and mania. Bipolar illness is characterized by sudden mood sways of a person which can abruptly shift from being highly irritable to being overly sad. The change from depression to mania and vice versa can occur in a very short period of time. The mood fluctuation in bipolar illness mainly follows a pattern for a person. Analyzing this pattern will help to foresee the next behavior of a person with bipolar illness.