If your GP thinks you may have bipolar disorder, they'll usually refer you to a psychiatrist, a doctor who specialises in mental health problems.
If your illness puts you at risk of harming yourself, your GP will arrange an appointment immediately.
You'll be assessed by the psychiatrist at your appointment. They'll ask you a few questions to find out if you have bipolar disorder. If you do, they'll decide what treatments are most suitable.
During the assessment, you'll be asked about your symptoms and when you first experienced them.
The psychiatrist will also ask about how you feel leading up to and during an episode of mania or depression, and if you have thoughts about harming yourself.
The psychiatrist will also want to know about your medical background and family history, especially whether any of your relatives have had bipolar disorder.
Depending on your symptoms, you may also need tests to see whether you have a physical problem, such as an underactive thyroid or an overactive thyroid.
If you have bipolar disorder, you'll need to visit your GP regularly for a physical and mental health review.
If you're diagnosed with the condition, it's important to talk to your psychiatrist so you're fully involved in the decisions about your treatment and care.
But a person is sometimes not able to make an informed decision about their care or communicate their needs, especially if their symptoms become severe.
If this happens, it may be possible to draw up an advance statement. An advance statement is a set of written instructions that state what treatments and help you want (or do not want) in advance in case you cannot communicate your decisions at a later stage.
Your GP or psychiatrist can give you further help and advice.