Panic Disorder: A mental health condition characterized by recurrent and unexpected panic attacks. A panic attack is an intense and sudden episode of fear or discomfort that reaches a peak within minutes and is accompanied by physical symptoms such as heart palpitations, sweating, trembling, shortness of breath, or a feeling of choking. Panic disorder is diagnosed when a person experiences recurrent panic attacks and has persistent anxiety and worry about having future panic attacks or their consequences, such as avoiding certain places or situations due to fear of having a panic attack.