Which disorder involves muscle tension, nervousness, and fainting as panic symptoms?

Panic disorder is characterized by recurrent and unexpected panic attacks, which are sudden episodes of intense fear or discomfort that typically reach a peak within minutes. Symptoms of a panic attack can include muscle tension, nervousness, and physical reactions like fainting or dizziness. This disorder is specifically marked by these intense episodes that often lead individuals to worry about future attacks or change their behaviors to avoid situations where they might experience a panic attack.

In contrast, while phobias involve intense fear of specific situations or objects, they do not necessarily include the broader range of symptoms like muscle tension and fainting. Generalized anxiety disorder (GAD) is characterized by excessive worry about various aspects of life but does not have the episodic panic attacks seen in panic disorder. Obsessive-compulsive disorder (OCD) involves intrusive thoughts and compulsive behaviors rather than the physiological responses associated with panic attacks. Thus, the definition and symptomatology of panic disorder align closely with the features described in the question.