The document defines anger as a strong negative emotion ranging from mild irritation to intense rage that is caused by feelings of injustice, mistreatment, or threat. It then discusses various origins and causes of anger, such as unmet expectations, faulty perceptions, personality traits, and poor communication skills. Finally, it provides tips for managing anger effectively, such as identifying triggers, reducing expectations, delaying responses, forgiving others, relaxation techniques, and developing communication and empathy skills.