I accidentally took an extra dose of lisinopril. one early in the morning and another just 3 hours ago. i am only suppose to take one a day. ?

Don't worry: It would be more helpful if you told us what strength, but in general high doses are well-tolerated. The worst thing that might happen is your blood pressure might temporarily get a bit lower than usual, so if you feel dizzy or lightheaded sit or lie down (but this is unlikely).

No problem: I assume your dose is most likely 10 or 20 mg. this should not cause you any harm.