Bilateral high flow in common carotid artery and internal carotid artery with normal end diastolic velocity and no stenosis. Is this normal?

How high is high? Increased flow without stenosis can happen if the cardiac output is very high or there is tortuosity if the arteries Generally don't worry until systolic velocity is over 200 cm/sec and even then it is probably ok with normal diastolic velocity why did you get the test? IF you are asymptomtic I would not worry too much.