I am getting light dizziness, partial faintness, light headache, loosing concentration, seriousness, 10% blur vision some times a day. I got faint 20 days back. then I did CT scan - OK, 24 Hrs Holter -OK, EEG -OK. Head up tilt table test (Not OK). Doctor advised me to have 25mg serlift for 1 month but due to this, i am feeling sleepy dizzy all the day. what could be the cause? any idea please.. ( myself Male, 33 age, 5.6 ft. 64 kg)