A mood disorder is a mental health condition that primarily affects a person's emotional state. It can cause significant changes in mood, leading to feelings of sadness, irritability, or extreme happiness. Common types of mood disorders include depression and bipolar disorder, which can disrupt daily life and relationships. These disorders can result from a combination of genetic, biological, environmental, and psychological factors. Symptoms may vary in intensity and duration, making it essential for individuals experiencing mood changes to seek help from a mental health professional for proper diagnosis and treatment options.