I suddenly feel sad or angry for no reason and at random times. My mood shifts that fast sometimes. What is wrong with me?

Moods are our emotions. They affect us every day. Sometimes we’re sad, other times we’re happy. We might even be sad and happy in the same day. But sometimes people’s mood can get “stuck” on sad. Or the moods might change a lot or become extreme. When this happens, it affects our lives. And it might be caused by a group of mental illnesses called mood disorders.