For people who already have heart disease, having just the right balance of salt and potassium in their urine — not too much, not too little — seems to be linked to the lowest chance of heart problems or dying from any cause. Too little or too much of this balance is linked to higher risks.

For people who already have heart disease, the more potassium their body gets rid of in urine, the more likely they are to have a heart attack, stroke, or die — which is the opposite of what most people think potassium does.

For people with heart disease, the more potassium their body gets rid of in urine, the higher their blood pressure tends to be — every extra gram of potassium excreted per day raises systolic pressure by about 1 point and diastolic by about 0.6 points, which is the opposite of what doctors usually expect.

When people pee out more salt than potassium, their blood pressure tends to be higher — it’s like the balance between salt and potassium in your urine tells you something about your blood pressure.

For people who already have heart disease, eating just the right amount of salt — not too little and not too much — seems to be linked to the lowest chance of heart problems or dying from any cause. Too little or too much salt might actually be riskier.

If you have pre-hypertension, having more sodium than potassium in your urine might mean you’re more likely to die from any cause — even if you’re not eating a ton of salt. It’s not just how much salt you eat, but the balance between salt and potassium that might matter more for living longer.