What causes high blood pressure ?

personally, I've heard the term "high blood pressure" a lot of times, 

but I am unsure of something.

Is high blood pressure caused by the same reason for everybody? 

I met somebody with high blood pressure and he told me all about the treatments and what he had to eat, but he never told me what caused it.

Are people born with it and it's just some sort of side effect ? 🤔 

Or do they all do exactly the same thing and that sort of triggers it? 

Thank you for reading ☺️ 

Hope my question is answered