system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is blood pressure important?

I notoriously have low blood pressure when I go to the doctors, and today they made a big deal because it was very low. I thought high blood pressure was bad.
gpt
Think of a hose, or pipes in your house leading to the shower.

Too low pressure and the liquid inside has trouble getting to the end at a decent pace.  In your house/hose this would mean your shower just dribbles water.  In your body, your farther parts don't get the oxygen they need.

Too high pressure and the pipes might burst, or your pump has to work too hard to push against the pressured liquid, and then the pump might stress and fail.  (In your body this is your veins/arteries and your heart)