Bipolar disorder, formerly called manic depression, is a mental health condition that causes extreme mood swings that include emotional highs (mania or hypomania) and lows (depression) according to the Mayo Clinic.
When you become depressed, you may feel sad or hopeless and lose interest or pleasure in most activities. When your mood shifts to mania or hypomania (less extreme than mania), you may feel euphoric, full of energy or unusually irritable. These mood swings can affect sleep, energy, activity, judgment, behavior and the ability to think clearly. Visit this link for more information.