system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why is blood pressure an important health metric? And how does sodium affect it?
gpt
High blood pressure can often indicate blockages in blood vessels, or hardened vessels, and this makes the heart work harder than it needs to. More work means the heart wears out faster.

Sodium affects blood pressure because it pulls water from the body into the blood. More water means more blood volume, and that's higher blood pressure.