My physician diagnosed me with allergies because of complaints of headache above eyes and dizziness/lightheadedness for a month. The lightheadedness is only when i sit up from a lying position. I am on Allegra-D. the heaches have basically stopped, but i still have the lightheadedness when sitting up or a sense of loss of balance when lying. Is this normal? she checked my blood pressures in lying, sitting and standing and there wasn't any orthostatic hypotension.