It can be. One of the biggest signs is if you can’t sleep at night or if you can function on very little sleep. Speaking very quickly or having several thought patterns at once. Go to this site and take this test, which is a generalized test. Healthyplace.Com/communities/depression/ni mh/bipolar_screening_test.Asp
if you have the signs of the illness, you need to seek out a qualified psychiatrist to get an official diagnosis and treatment plan.

Bipolar disorder is a mood disorder characterized by alternating states of depression and mania that follow each other in a repeating cycle.

People with bipolar disorder may cycle through these states quickly or may experience long periods of depression or mania. Often one mood state predominates, while the other occurs only infrequently or briefly.

Symptoms of the elevated mood stage of bipolar disorder include an exaggerated sense of confidence and well-being, racing thoughts, excessive talking, distractibility, increased desire for pleasurable activity, decreased need for sleep, impulsivity, irritability, and impairment in judgment. The depressed phase includes symptoms of sadness, fatigue, pessimism, feelings of helplessness, low self-esteem, and loss of interest in life, possibly with thoughts of suicide.