Since 3 weeks ive been suffering from episodes of sudden dizziness that does not last more than one minute but that is followed by nausea and sometimes palpitations and rapid breath.I have done some blood tests incincluding cbc, ferritin, vitamin b12, TSH, T3and T4. All results were normal. What could be the reason behind such repeated episodes of dizziness? Note: such symptons appear once or twice a week and less when I am relaxed.