Salt Sensitivity and Blood Pressure: What You Should Know

Two people can eat the same salty meal and have completely different blood pressure responses. One barely moves, the other jumps. That difference often comes down to something called salt sensitivity.¹
Understanding how your body reacts to salt can make a real difference to how you manage your blood pressure and protect your heart over time.¹²

What is salt sensitivity?

Salt sensitivity describes how strongly your blood pressure responds when you change your sodium intake.¹

If you are salt sensitive, your blood pressure tends to go up when you eat more salt and down when you cut back.¹

If you are salt resistant, your blood pressure stays relatively stable, even when your salt intake varies.¹

In research studies, salt sensitivity is usually tested by putting people on a low sodium diet and then a higher sodium diet and comparing the change in blood pressure. If blood pressure rises noticeably on the higher salt phase, that person is considered salt sensitive.¹²

Salt sensitivity is not a disease. It is a trait that reflects how your kidneys, blood vessels, hormones, nervous system and genes handle a load of sodium. In salt sensitive people, the kidneys do not get rid of extra sodium as efficiently and the blood vessels may stay more constricted. The result is more fluid in the circulation and higher pressure inside the arteries.¹²

It is also not all or nothing. Some people are very salt sensitive, some mildly, some barely at all.¹ At the moment there is no simple clinic test to diagnose salt sensitivity.¹² In everyday life, you might suspect you are salt sensitive if:

• Your blood pressure drops clearly when you follow a low sodium diet

• Your readings spike after several salty meals or a high salt holiday

Over the long term, people who are salt sensitive appear to have a higher risk of developing hypertension, heart disease and kidney problems compared with people whose blood pressure is more salt resistant.¹²⁴

How common is salt sensitivity and who is more at risk?

Salt sensitivity is more common than many people realise. Research suggests that roughly:

• About one in four people with normal blood pressure are salt sensitive

• About one in two people with hypertension are salt sensitive¹²

It also tends to show up more often in certain groups, including:

• Older adults – blood vessels and kidneys become less flexible with age¹²

• Women in some studies¹²

• People of African or East Asian background¹²⁴

• Individuals with obesity²

• People with chronic kidney disease or diabetes¹²

These factors increase the likelihood of salt sensitivity but do not guarantee it. You can have high blood pressure and still be relatively salt resistant. You can also be salt sensitive even if your current blood pressure is in the normal range, especially if you keep your salt intake low.¹²

Importantly, salt sensitivity itself seems to be a risk factor. Even if your numbers look fine now, a salt sensitive person who regularly eats a high salt diet is more likely to develop hypertension and cardiovascular problems over time.¹²⁴

How much difference does cutting salt make?

On average, eating less salt produces a modest but meaningful drop in blood pressure. Large analyses of clinical trials show that when people reduce their sodium intake by the amount you would expect going from a high salt diet to a more moderate one, systolic blood pressure typically falls by a few points.³⁴ The effect is usually:

• Bigger in people with high blood pressure

• Smaller but still helpful in people with normal blood pressure³

For someone who is very salt sensitive, the drop can be quite impressive, sometimes 8–10 mmHg or more.¹²³ For someone who is salt resistant, the change may be smaller, but over years even a small reduction in blood pressure can translate into fewer strokes and heart attacks at a population level.³⁴

There has been some debate around very low sodium intakes, but randomised trials have not shown harm from moderate sodium reduction.³ Current expert guidance does not suggest that people need to eat above recommended limits to stay safe.²⁴⁵⁶

Most adults in high income countries consume far more sodium than recommended, mostly from processed foods, bread, cured meats, cheeses, snack foods and restaurant meals rather than from the salt shaker at home.²⁴⁵⁶ That means almost everyone has room to cut back.

What does this mean for your daily life?

You do not have to know for sure whether you are salt sensitive to benefit from eating less salt. For most people with or at risk of high blood pressure, major organisations recommend:

• Keeping sodium below about 2,000–2,300 mg per day (around 5 g of salt, or one teaspoon)⁴⁵⁶

• Aiming for around 1,500 mg per day if you already have hypertension or are in a higher risk group, if this is realistic and safe for you personally⁴⁶

Practical steps that help:

• Cook more at home using fresh or minimally processed ingredients

• Check labels and choose lower sodium versions of bread, stock, sauces and snacks

• Flavour with herbs, spices, garlic, lemon and pepper instead of always reaching for the salt

• Be cautious with cured meats, instant noodles, takeaways and salty snacks, which can all be very high in sodium

• Combine salt reduction with other habits that lower blood pressure, such as eating more fruit and vegetables, following a DASH-style pattern, moving regularly, managing weight and limiting alcohol²⁴

If you monitor your blood pressure at home, you can see how your body responds. A clear drop after a few weeks of lower sodium suggests that salt is a key driver for you and is worth prioritising long term. If the change is smaller, salt still matters, but you may want to focus more attention on other levers such as physical activity, sleep, stress management and medicines prescribed by your doctor.¹²⁴

Take-home message

Salt sensitivity helps explain why some people seem to be “salt magnets” for high blood pressure while others are not.¹² Even so, the overall message is consistent: for most adults, especially those with or at risk of hypertension, eating less salt is a simple, low-cost step that supports healthier blood pressure and better heart health over time.²⁶

Always talk to your doctor or health professional before making major dietary changes or adjusting any medication.

References

1. Elijovich, Fernando, Eduardo L. Weinberger, Theodore W. Kurtz, et al. “Salt Sensitivity of Blood Pressure: A Scientific Statement from the American Heart Association.” Hypertension (2016).

2. Grillo, Andrea, Luciano Salvi, Paolo Coruzzi, Paolo Salvi, and Gianfranco Parati. “Sodium Intake and Hypertension.” Nutrients 11, no. 9 (2019).

3. Filippini, Tommaso, Marco Malavolti, Nicola W. R. Andrews, et al. “Blood Pressure Effects of Sodium Reduction: Dose–Response Meta-Analysis of Experimental Studies.” Circulation 143 (2021).

4. Youssef, Georges S. “Salt and Hypertension: Current Views.” E-Journal of Cardiology Practice 22 (2022). European Society of Cardiology.

5. World Health Organization. Guideline: Sodium Intake for Adults and Children. Geneva: World Health Organization, 2012.

6. American Heart Association. “How Much Sodium Should I Eat per Day?” Heart.org.