Decision Guide

Sodium and Blood Pressure

Reducing sodium can lower blood pressure for many people, although the size of the response varies. This page explains how sodium affects blood pressure, where most sodium comes from, and how to use general intake targets without treating one number as appropriate for everyone.

Written and approved by N. J. Sorensen, RDN, LD. General nutrition education; not individualized medical nutrition therapy.

Key sources: American Heart Association sodium guidance; NHLBI DASH Eating Plan; FDA Sodium in Your Diet; and the KDIGO 2024 CKD guideline.

Use Case

This page is for adults who want a practical sodium target for preventing or managing high blood pressure. People with kidney disease, heart failure, or another condition that affects fluid and electrolyte balance should follow the target established by their health care team.

Snapshot

What this page covers:

What sodium does to blood pressure
How much sodium matters
Where sodium comes from in the diet
The DASH default for most adults

The Mechanism

Sodium helps regulate fluid balance. When sodium intake rises, the body temporarily retains additional water while the kidneys work to excrete the excess sodium. The added fluid can increase the volume of blood moving through the circulation.

The kidneys normally respond by excreting more sodium and water. Blood pressure can rise when that response is incomplete or when the blood vessels do not accommodate the change in volume effectively. This response varies among individuals and is often described as sodium sensitivity.

Controlled feeding trials show that lowering dietary sodium can reduce blood pressure in people with and without hypertension. Average reductions are generally larger among people who already have high blood pressure, but individual responses vary.

How Much Sodium to Aim For

For most adults, use less than 2,300 mg per day as the general practical ceiling. This aligns with federal public-health guidance and with one of the sodium levels used in the DASH eating plan.

The American Heart Association describes 1,500 mg per day as an optimal goal for most adults, particularly those with high blood pressure. NHLBI also notes that the 1,500 mg DASH level can lower blood pressure further than the 2,300 mg level. That does not make 1,500 mg a universal prescription: feasibility, medical conditions, medications, symptoms, and treatment plans still matter.

If current intake is substantially higher, reducing sodium by about 1,000 mg per day can be a meaningful and more workable first step.

People with kidney disease, heart failure, or another condition affecting fluid or electrolyte balance may need an individualized sodium and fluid plan.

Where Sodium Comes From

Most dietary sodium in the United States comes from packaged, prepared, and restaurant foods. Salt added during home cooking still contributes, but it is usually not the largest source. This makes food-label comparison, lower-sodium product selection, and restaurant choices the highest-yield places to begin.

The most useful comparison points are foods eaten often or in large portions:

Deli and cured meats, canned soups, frozen entrées, sauces, and restaurant meals can provide a large amount in one serving.
Bread, cheese, condiments, and mixed dishes may provide smaller amounts that add up across the day.
Standard and no-salt-added versions of beans, vegetables, broths, and tomatoes can differ substantially.
Serving size matters: eating two labeled servings doubles the listed sodium.

On the Nutrition Facts label, 5% Daily Value or less is considered low in sodium and 20% or more is considered high.

DASH makes sodium reduction easier by shifting the routine food pattern toward vegetables, fruits, beans, whole grains, unsalted nuts and seeds, and lower-sodium packaged foods. The complete DASH pattern lowers blood pressure, and reducing sodium can add further benefit.

The Default

For most adults, start by moving toward less than 2,300 mg per day. Compare the packaged foods you eat most often and reduce high-sodium restaurant and takeaway meals before treating the salt shaker as the whole problem.

What the Evidence Shows

Reducing sodium lowers blood pressure for many people, but the size of the response varies. Controlled feeding research also shows that sodium reduction and the complete DASH pattern reinforce each other; the largest blood-pressure reduction tested occurred with DASH at the lower sodium level.

The commonly cited numbers serve different purposes. Less than 2,300 mg per day is the general federal limit and a standard DASH level. The American Heart Association describes 1,500 mg as an optimal goal for most adults, while KDIGO’s suggestion of less than 2,000 mg applies specifically to people with chronic kidney disease and carries condition-specific exceptions.

Why It Matters

For most adults, reducing the major sources of sodium is more useful than pursuing a perfect number on day one. Medical conditions, medications, symptoms, heavy sweat losses, and prescribed treatment plans can change the appropriate target.

Sources

American Heart Association — How Much Sodium Should I Eat Per Day?: 2,300 mg ceiling, 1,500 mg optimal goal, and the practical 1,000 mg reduction.
NHLBI — Health Benefits of DASH: DASH and DASH-Sodium evidence in plain language.
Sacks and colleagues, 2001 — DASH-Sodium trial: controlled comparison of DASH across sodium levels.
FDA — Sodium in Your Diet: Daily Value, label interpretation, and major food-source framing.
KDIGO 2024 CKD guideline executive summary: CKD-specific sodium suggestion and sodium-wasting exception.

Boundary Conditions

High blood pressure: The American Heart Association recommends no more than 2,300 mg per day and describes 1,500 mg as an optimal goal for most adults, especially those with high blood pressure. If that change is not currently workable, reducing intake by about 1,000 mg per day can still be meaningful.

Chronic kidney disease: KDIGO 2024 suggests less than 2,000 mg of sodium per day for people with CKD, a 2C recommendation. The plan still needs to fit kidney function, medications, nutritional status, and the type of kidney disease. Dietary sodium restriction is usually not appropriate in sodium-wasting nephropathy.

Heart failure: People with heart failure may receive an individualized sodium and fluid plan based on symptoms, congestion, medications, and clinical status. Follow the target established by the heart-failure care team.

Prolonged activity or heat exposure: A lower population target may not fit competitive athletes, heavy sweaters, or people working for prolonged periods in high heat. Sodium and fluid needs in these settings depend on sweat losses, duration, fluid intake, symptoms, and recovery demands.

Prescribed sodium or fluid plans: People taking diuretics or other medications that affect fluid balance should follow any sodium or fluid instructions provided by their health care team.

The population default is less than 2,300 mg per day. Clinical conditions may change how that default is applied.

Connects To

DASH Diet Guide — The full DASH food pattern applying this sodium target across all food categories
Best Diet Pattern for Blood Pressure — Decision between dietary patterns for cardiovascular dietary intervention
Diet Patterns Guide — Comparison of major evidence-based dietary patterns
DASH Vegetable Bean Soup — A low-sodium application using no-salt-added ingredients

Bottom Line

Excess sodium can raise blood pressure, and reducing it can help many people. For most adults, less than 2,300 mg per day is a practical general ceiling, with the highest-yield changes usually coming from packaged, prepared, and restaurant foods. Lower or condition-specific targets should be matched to the person’s health needs and treatment plan.