My long term breathlessness (for a week) seems to settle with xanax, (alprazolam) is xanax (alprazolam) masking an underlying lung issue?

Probably not: It is probably anxiety that i causing the breathlessness. Learn relaxation techniques. See a psychiatrist who can help with further management including medications if needed. A therapist can help with learning new coping techniques.

Anxiety d/o: Very suggestive of anxiety d/o. Pts also complain of various combinations of other physical symptoms i.e. Dry mouth, nausea, cramps, diarrhea, chest pain, sweating, difficulty swallowing, tingly sensations, hot flashes , chills, blurred vision, tunnel vision, dizziness, poor concentration. Treatment is available, we usually use other meds not xanax (alprazolam). Meds and therapy are most effective , good luck.