People with bipolar disorder will experience periods of depression as well as mania, feelings of extreme high. Many people will also have long periods of feeling healthy.
The condition can be triggered by stressful events, such as work or family pressures. There is some evidence suggesting a genetic link to the disorder.
Periods of depression are similar to other kinds of depression, where people experience low mood and lack of energy. Some people will have suicidal thoughts. Around a third of people with bipolar disorder harm themselves or attempt suicide at some point.
The extreme high of mania can make people feel 'wired'. Their mind will race, they may talk quickly, and have difficulty with sleeping. Some people behave impulsively during these periods. In some cases, people may believe that they have special abilities.
Around one percent of adults will have episodes of bipolar disorder at some point in their lives. It can be difficult to diagnose, so treatment is often delayed.
Treatments can include medication as well as talking therapies and self-management, such as keeping a mood diary. Many people with bipolar are able to manage their condition and live fulfilling and productive lives.
You can find out more about the definition of bipolar disorder from the Royal College of Psychiatrists.
You can find our more about self-management of bipolar disorder here.