civil rules (air nav order)state not below 500 feet above any person, vehicle, vessel or structure unless for purpose of take off or landing....if mil then this i remember was about 250ft(low fly, correct me if i am wrong ). If you genuinely have reason to believe you got a problem then see your gp.
if you need to follow up log all details, times etc. there is a line re low flying complaints.....google it you should find it.
couldn't be worse than a nimrod on take off, 100 yard from my room
