The bipolar disorder is characterized by the cyclic mood swings. As the name says, it swings the mood of the person in between the two extremes, elevation and depression. Bipolar disorder is caused by the imbalances in certain brain chemicals called neurotransmitters, which can be due to some genetic, biochemical or environmental factors.

The periods of highs and lows or ups and downs in a person suffering from bipolar disorder, are called the episodes of mania and depression.

Depression: A type of sadness, feeling of fatigue, mood swings, irritability, empty mood, restlessness, helplessness and a guilty consciousness or worthlessness all comes under this category. The people who have depression can lose the pleasure or interest in the daily activities and entertainments. They will be tearful and feel some anxiety, but often are not aware of the reason for that tension. They too feel the distractibility in the things they do. The worst characteristic they have is the predominant suicidal thoughts. They can attempt suicide or deliberately put themselves in the things which can cause death or injuries. They may find a change in the appetite which can also lead to unintended weight loss or weight gain. Some people find some chronic pain or the other difficulties which are not due to the physical illness or injuries. If any of these five or more characteristics occurs in a person for almost every day for two weeks or a longer time, it can be due to the illness called depression.

Mania: The first symptom of having a mania is hyper excitability - an increased level in the energy and activities. The person can feel that he is excessively good or overly supreme as he will be going through a euphoric mood. But the elevated mood of the person can finally lead to irritability and depression. He or She may talk fast and often can be unrealistic in their own ability or power. Their judgment and decision making power will be poor. They also have racing thoughts but will find unable to concentrate on anything they do. They also feel a decreased want for sleep. The tendency to spend more also can be there. The sexual drive for these people can also decrease. They also acquire an exaggerated level of optimism. Behavior becomes more aggressive and can have a tendency to deny anything and everything. If any three or more of these symptoms are shown in a person for almost every day for one week or longer, it can be due to mania which should be treated properly.

There are so many classifications for bipolar disorder according to the severity:

1. Bipolar 1 disorder - is the classic form of the illness which includes one or more manic episodes which can or not be followed with major depression episodes.
2. Bipolar 2 disorder - do not have severe mania but some milder episodes of hypomania with alternate depression.
3. Cyclothymia - is a mild form of the bipolar 2 disorder which includes hypomania (the mild to moderate level of mania. If not treated properly, it can lead to severe mania and depression) and dysthymia (if a mild low mood lasts long in a person, it is called dysthymia).

Severe mania or depression can also lead to psychotic problems including hallucinations and delusions.