For healthy young people, eating more or less salt doesn’t seem to make their blood pressure bounce around more or less — their blood pressure stays steady no matter how much sodium they pee out.

People who pee out more salt tend to have higher blood pressure, and this pattern shows up in lots of different groups of people around the world.

If you have heart disease and eat more salt, your blood pressure tends to go up — for every extra gram of salt you excrete in urine, your top blood pressure number goes up by about 1.3 points and your bottom number by about 0.5 points.

Eating a lot of salt for 10 days might make the pressure in your main arteries bounce around a bit more, but it’s not clear yet—more research is needed to see if it affects your core arteries differently than your arm blood pressure.

In people with high blood pressure in Shanxi Province, those who excrete more sodium in their urine tend to have higher blood pressure—even when you account for things like age, weight, diabetes, and cholesterol—and this link is even stronger in women.

Even though people urinate out more salt after drinking this mineral water, their blood pressure doesn’t go up — meaning the body’s salt removal system works fine without raising BP.