Reference
Sodium and Blood Pressure: The Numbers That Matter
Sodium and blood pressure are tightly linked, and both have clear numbers you can work with. This guide states the daily sodium target, the standard blood pressure categories, and the eating habits that move the sodium number without making food taste like salt water.
The sodium numbers
The World Health Organization states the same boundary in a different unit, which is a common source of confusion. WHO recommends less than 2 grams of sodium per day for adults, which equals about 5 grams of salt. The conversion is that table salt is roughly 40% sodium by weight, so 5 g of salt contains about 2 g of sodium, and 1 g of salt contains about 400 mg of sodium. Conversely, 2,300 mg of sodium is about 5.8 g of salt, or just over one level teaspoon. If a guideline names sodium in milligrams and another names salt in grams, they are usually describing nearly the same boundary.
- FDA Daily Value and Dietary Guidelines limit: less than 2,300 mg of sodium per day
- Lower target associated with additional benefit: 1,500 mg per day
- WHO limit: less than 2 g of sodium, about 5 g of salt per day
- Table salt is about 40% sodium by weight: 1 g salt = about 400 mg sodium
- On a label, 'low sodium' means 140 mg or less per serving
The blood pressure numbers
One reading is not a diagnosis. Blood pressure is normally assessed from the average of two or more readings taken on two or more occasions, because it moves with caffeine, stress, a full bladder, a recent meal, posture and time of day. Measure after sitting quietly for a few minutes, feet flat, arm supported at heart level, with a cuff sized for your arm.
- Normal: under 120/80 mm Hg
- Elevated: 120 to 129 systolic and under 80 diastolic
- Stage 1: 130 to 139 systolic or 80 to 89 diastolic
- Stage 2: 140 or higher systolic or 90 or higher diastolic
- Above 180 and/or above 120 mm Hg: seek prompt medical attention
How the two are connected
Potassium works partly in the opposite direction, and the NHLBI notes that adequate potassium helps the kidneys shed sodium and relaxes vessel walls. The Daily Value for potassium is 4,700 mg, and typical U.S. intake falls well short of it, which is the same shortfall discussed under fibre and micronutrients: the dietary fix is more plants, not only less salt.
Cutting sodium without eating cardboard
Most sodium in the U.S. diet comes from packaged, prepared and restaurant food rather than from the salt shaker at the table, so trimming the shaker is the least productive move available. Bread and rolls are consistently among the largest single contributors, not because bread is salty but because it is eaten every day in quantity. Deli meat, pizza, sandwich mains, soup, canned beans that are not rinsed, soy sauce, deli salads, cheese, and boxed mixes are the other recurring places.
What works in practice: buy no-salt-added or low-sodium canned goods and rinse canned beans under running water, which removes a substantial share of the added sodium; compare two products in the same category on the sodium row, where differences of two- or three-fold are common; cook more meals at home, where you control the salt; and use acid, heat and aromatics to carry flavour instead, with citrus juice, vinegar, garlic, onion, herbs and pepper doing most of the work. Salt added during cooking is more efficient than salt added at the table, because its flavour reaches the whole dish, so a smaller amount is needed.
One caution: the advice above is population-level guidance. Someone with heart failure, kidney disease, or a specific medication regimen may have been given a particular sodium target, and very low sodium intake is not automatically better for everyone. Persistent symptoms or a blood pressure reading in a higher category belong with your own clinician rather than with a reference page.
- Compare similar products on the sodium row; differences are often two- or three-fold
- Buy no-salt-added canned goods and rinse canned beans
- Bread, deli meat, pizza, soup, cheese and sandwich mains are the usual large sources
- Use citrus, vinegar, garlic and herbs so less salt is needed for the same perceived flavour
Updated 2026-10-07
