You're the flight surgeon. Anxiety.

Anxiety is a medical mimicker that can imitate both cardiac and neurological symptoms. Anxiety disorder research protocols regularly use hyperventilation or i.v. lactate infusion to trigger panic attacks in susceptible subjects. Susceptible patients experience panic attacks with slight decreases in CO2 or increases in lactate production seen in mild exercise such as stair climbing. To the unsuspecting physician this appears to be dyspnea on exertion. Hyperventilation during rapid eye movement (dream) sleep may trigger panic attacks in patients with panic disorder, mimicking paroxysmal nocturnal dyspnea. Syncope from panic-induced hyperventilation can mimic seizures. When panic-like anxiety is discovered in aircrew it necessitates grounding. The prognosis is frequently good after treatment with psychotherapy, with return to full flying status a strong possibility.