In dance class,i really felt like i might pass out. i was seeing spots, hyperventilating, & had to sit. is this a serious zoloft (sertraline) effect? i am worried.

Anxiety: Sounds more like a panic attack. When you start to hyperventilate your body blows off carbon dioxide and that can cause your blood vessels to constrict. That causes the feeling of "passing out", visual spots and weakness. The mechanism is real. Continue your activities. Dance is excellent for exercise and relaxation. Stick with your meds. If symptoms are recurrent let your doctor know.