Is the altitude high? do you need to take med for it? Can ppl with HBP visit JiuZhaiGou?

Jiuzhaigou does not have a very high altitude and most people can adapt to it, so do not worry about it. You do not need to take the medicine with you. If you feel sick, you can hire a ox oxygen bag there.
If you have HBP, you should be more careful. The altitude still has some effect on you.