Blood pressure monitor showing a reading

Sodium & Blood Pressure

Sodium and blood pressure are closely connected. Major health authorities consistently identify higher sodium intake as a factor that can raise blood pressure, and they support reducing excessive sodium intake as a way to lower it.

This page focuses specifically on what authorities and research say about sodium and blood pressure. It is not a general guide to diagnosing or treating high blood pressure.

How Sodium Can Raise Blood Pressure

The FDA explains that sodium attracts water. Consuming a high-sodium diet can draw more water into the bloodstream, increasing blood volume. Greater blood volume means the heart must work harder to move blood through the body, which can increase blood pressure.

The NIDDK provides a complementary explanation: excess sodium can cause the body to retain additional fluid, which can raise blood pressure and place extra strain on the kidneys.

Higher sodium intake can raise blood pressure.
Reducing excessive sodium intake can lower blood pressure.

Sodium is not the only factor that affects blood pressure, and individual responses can vary. The relationship is consistent across major health authorities, but it does not mean that every person experiences the same degree of change.

What the Major Health Authorities Say

U.S. Food and Drug Administration (FDA)

The FDA states that diets higher in sodium are associated with an increased risk of developing high blood pressure. The FDA also explains the mechanism: sodium attracts water, and a high-sodium diet can increase blood volume, which in turn can raise blood pressure.

Centers for Disease Control and Prevention (CDC)

The CDC states that consuming too much sodium can raise blood pressure and that limiting sodium can help lower it.

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NIDDK explains that too much sodium can contribute to fluid retention and high blood pressure. NIDDK also identifies reducing sodium as important for blood-pressure management.

American Heart Association (AHA)

The AHA supports reducing sodium intake to lower blood pressure. The AHA has published research finding that reducing sodium can improve blood pressure. The AHA’s specific sodium recommendations are listed in the Sodium Recommendations section below.

World Health Organization (WHO)

“Excess sodium intake leads to increased blood pressure.”
— World Health Organization — Sodium reduction

WHO identifies raised blood pressure as the primary health effect associated with high-sodium diets. WHO supports reducing sodium intake to reduce blood pressure.

European Food Safety Authority (EFSA)

EFSA identifies elevated blood pressure as the major adverse effect associated with increased sodium intake and describes a positive relationship between sodium intake and blood pressure. EFSA also recognizes that the blood-pressure response to sodium can be influenced by other factors and may vary between individuals.

What Research Has Found

The National Institutes of Health (NIH) has published findings from a controlled study on sodium and blood pressure that illustrate the relationship clearly.

Study — NIH Research Matters: “Lower sodium could reduce blood pressure in most people”

The study involved 213 adults ages 50–75. Participants followed a high-sodium diet and a low-sodium diet and had their blood pressure measured after each diet period.

What NIH reported:

"Nearly 75% of participants had lower systolic blood pressure"

on the low-sodium diet than on the high-sodium diet.

NIH reported an average difference of 7 mm Hg between the high- and low-sodium diets.

between the high- and low-sodium diets. A 7 mm Hg reduction means the upper (systolic) blood-pressure number was 7 points lower on average in this study.

Compared with participants’ usual diets, 72% had lower systolic blood pressure on the low-sodium diet, with an average reduction of 6 mm Hg — approximately 6 points lower in the upper blood-pressure number.

"The effect of dietary sodium didn’t depend on whether a person had high blood pressure to begin with."

NIH also reported that the effect was not dependent on whether participants were taking blood-pressure medication. This is a study finding; it is not guidance about medication.

These are findings from a controlled study. They are not instructions for every person to reduce sodium by a specific number of milligrams. An individual should not expect to experience exactly a 6- or 7-point reduction.

Research findings establish what was observed in a study population. They contribute to the broader scientific understanding of sodium and blood pressure, but they are different from universal recommendations.

Why the Effect Is Not Exactly the Same for Everyone

“The sensitivity of blood pressure to sodium … varies from person to person.”
— NIH

EFSA also recognizes that the blood-pressure response to sodium can be influenced by other characteristics and circumstances.

Research can establish a clear overall relationship between sodium and blood pressure without predicting exactly how much an individual’s blood pressure will change.

The overall direction of the relationship — higher sodium associated with higher blood pressure, and sodium reduction associated with lower blood pressure — is consistent across major authorities and research. The magnitude of the change for any specific individual is a different question.

Sodium Recommendations

Major health authorities publish sodium reference values that reflect their own methodologies and purposes. These values are not interchangeable, and none of them is automatically an individual medical prescription.

Authority	Sodium reference
U.S. Food and Drug Administration (FDA)	2,300 mg/day — Daily Value for adults
Centers for Disease Control and Prevention (CDC)	Less than 2,300 mg/day for teens and adults
American Heart Association (AHA)	No more than 2,300 mg/day; optimal goal of no more than 1,500 mg/day for most adults
World Health Organization (WHO)	Less than 2,000 mg/day for adults
European Food Safety Authority (EFSA)	2,000 mg/day — safe and adequate intake for the general EU adult population

My Sodium Today uses the FDA Daily Value of 2,300 mg of sodium for adults as its primary tracking reference — the same value used on U.S. Nutrition Facts labels. See References for the specific sources behind each authority’s position.

What My Sodium Today Tracks

My Sodium Today tracks the sodium a user records in their meals. It displays that sodium in two equivalent forms:

Milligrams (mg) — the absolute amount of sodium consumed
% of the FDA Daily Value for adults — the same amount expressed relative to 2,300 mg

These are two representations of the same quantity. My Sodium Today does not:

Measure blood pressure
Diagnose high blood pressure
Determine whether a person's blood pressure is caused by sodium
Predict an individual's blood-pressure response to sodium
Provide treatment recommendations

The Blood Pressure section on the homepage allows you to record blood-pressure readings as a personal log. Those readings are stored locally on your device and are not interpreted or analyzed by the application.

Bottom Line

Higher sodium intake can raise blood pressure, and reducing excessive sodium intake can lower blood pressure.

Research has demonstrated this effect in people with and without high blood pressure. Individual responses vary, but the overall direction of the relationship is consistent across major authorities and study findings.

There is an important distinction between tracking sodium intake and determining what that sodium intake means for an individual’s health. My Sodium Today does the first. It does not attempt to do the second.

Sources

U.S. Food and Drug Administration (FDA) — Sodium in Your Diet
Centers for Disease Control and Prevention (CDC) — About Sodium and Health
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) — sodium, fluid balance, and blood pressure resources
American Heart Association (AHA) — sodium and blood pressure guidance
World Health Organization (WHO) — Sodium reduction
European Food Safety Authority (EFSA) — scientific assessment of sodium and adverse health effects
National Institutes of Health (NIH) — Lower sodium could reduce blood pressure in most people (NIH Research Matters)

See References for the specific documents and links.

Disclaimer: My Sodium Today provides general information and personal sodium tracking. It does not provide medical advice, diagnosis, or treatment. Sodium recommendations and blood-pressure information may not apply to every individual. If a healthcare professional has given you specific dietary or medical instructions, follow those instructions.