Is Salt Really Bad for Your Blood Pressure? Here’s What You Need to Know.

11 July 2025

How salt affects our blood pressure is more nuanced than what people might typically think. Just like too much salt can raise blood pressure, too little of it may increase the risk of heart disease and diabetes.

Salt is one of many ingredients that’s often singled out because we’ve been told it’s bad for our hearts. But does it really affect blood pressure? If yes, how? In this article, we’ll learn about blood pressure, how (much) salt affects it, and what changes we can make to keep our heart healthy and blood pressure in check.

A Quick Overview of Salt and Its Functions

The salt we consume comprises sodium and chloride. It’s used to enhance flavour and preserve foods.

Our body needs a small amount of sodium to maintain the appropriate volume of blood and other body fluids. Sodium is also essential for normal nerve and muscle function.

Too much salt can increase blood pressure and the risk of stomach cancer. On the other hand, taking too little salt has been associated with a higher risk of heart disease and diabetes. Likewise, a low salt diet can result in low blood pressure, dehydration, and increased blood fat levels.

What Is Blood Pressure?

With each heartbeat, your heart pumps blood into arteries that transport oxygen and nutrients to each cell. Blood pressure is the force of your blood pushing against your artery walls each time your heart beats and rests.

There’re two numbers in the blood pressure reading.

  • Systolic pressure:The top/first number is the pressure when your heart beats.
  • Diastolic pressure: The bottom/second number shows the pressure when your heart rests between beats.

For example, a reading of 120/80 mmHg, which is considered normal, means your systolic pressure is 120 mmHg and diastolic pressure is 80 mmHg. You can get your blood pressure measured at home, in pharmacies, and clinics.

According to the NHS, the categories for adults are: (1)

Normal blood pressure

Between 90/60 mmHg and 120/80 mmHg.

High-normal or pre-hypertension

120/80 mmHg to 140/90 mmHg.

High (Hypertension)

  • Stage I: Between 140/90 mmHg and 160/100 mmHg.
  • Stage II: Between 160/100 mmHg and 180/120 mmHg.
  • Stage III: Systolic over 180 mmHg or diastolic over 120 mmHg (severe hypertension).

High blood pressure (hypertension) is common in the UK, affecting about 32% of adults. Even worse, nearly 3 in 10 of these (about 4.2 million people in England) don’t know if they’ve hypertension.

How Does Salt Affect Blood Pressure?

Salt can affect your blood pressure in several ways.

First, sodium in salt helps regulate fluid balance in the body. However, too much sodium in your bloodstream causes the body to retain water. This extra water increases the volume of blood in the vessels, raising blood pressure.

Over time, this added pressure puts strain on the heart, arteries, and kidneys.

Second, taking too much sodium may make your blood vessels (arteries) stiff. (2) Arterial stiffness can be a cause or consequence of high blood pressure.

For instance, long-term high blood pressure can damage arterial walls by increasing inflammation and collagen fibres, and by decreasing elastic fibres. On the other hand, arterial stiffness may raise blood pressure by promoting calcium buildups in the heart muscle and valves. (3)

Third, emerging evidence suggests that high dietary sodium may alter the balance of gut microorganisms in the stomach and intestines. This imbalance—gut dysbiosis—can increase inflammation, potentially raising blood pressure. (4,5)

The link between salt intake, gut microorganisms, and blood pressure is an area of research. Hence, we need large, controlled trials to establish a clear link and underlying mechanisms.

Salt Can Increase Your Blood Pressure, But There’s A Catch

High salt intake typically increases blood pressure, but this isn’t true for everyone.

In some individuals, blood pressure changes depending on the amount of salt they take. Doctors call them “salt sensitive”.

According to Harvard Health Publishing, nearly 60% of individuals with high blood pressure fall into this category. (6) Switching from a low-salt diet to a high-salt diet increases blood pressure by about 5 points in these individuals.

Interestingly, about 10% of individuals have inverse salt sensitivity. In those individuals, blood pressure drops with a low salt intake.

Sadly, it’s hard to differentiate between salt-sensitive and salt-resistant individuals. Still, we know that UK residents consume a lot more sodium than recommended, so it’s safe to say that one should reduce their salt intake, regardless of their salt sensitivity.

High salt intake is a significant yet a modifiable risk factor for high blood pressure and heart disease. Reducing salt intake is one of the most cost-effective public health interventions for reducing heart disease and stroke, says the World Health Organization (WHO). (7)

How Much Salt Is Too Much?

In the UK, the NHS recommends adults consume no more than 6g of salt per day, about one teaspoon. However, most adults exceed this amount. According to Public Health England data, an average individual in the UK consumes 8.4g per day (8).

Where is all this salt coming from?

Around 75% of the salt we consume is already in the foods we buy, not what we add at the table. Common high-salt culprits in UK diets include:

  • Processed meats (bacon, ham, sausages)
  • Ready meals
  • Takeaway pizzas
  • Canned soups
  • Cheese
  • Crisps and savoury snacks
  • Bread and breakfast cereals

Even foods you wouldn’t expect, like shop-bought sandwiches or sauces, can have surprisingly high salt levels.

The Compound Effect of a High-Salt, Processed Food Diet

When people regularly eat meals high in salt, especially processed foods, it has a compound effect on blood pressure over time. This isn’t just about one salty takeaway; it’s about the gradual, cumulative impact of daily excess sodium on your cardiovascular system.

A diet dominated by processed foods also tends to ‘crowd out’ healthier options like fresh fruit, vegetables, whole grains, and unsalted nuts. This means people consume fewer nutrients that actually help control blood pressure, such as potassium, magnesium, and dietary fibre.

Are Fruits and Vegetables Really That Important?

Yes.

Fruits and vegetables are rich in potassium, a mineral that helps balance out the effects of sodium by encouraging the body to excrete excess sodium through urine. This, in turn, helps to relax blood vessels and lower blood pressure.

A large meta-analysis published in the British Medical Journal found that increasing potassium intake significantly reduces blood pressure, particularly in individuals with hypertension (9). The NHS recommends aiming for at least 5 portions of fruit and vegetables per day, though more is often better.

Foods That Can Help Lower Blood Pressure

Certain foods have been shown to help lower or regulate blood pressure thanks to their nutritional content:

  • Leafy greens: High in potassium and magnesium.
  • Beetroot: Contains nitrates that relax blood vessels.
  • Berries: Rich in antioxidants called anthocyanins.
  • Oily fish (e.g. salmon, mackerel): Contains omega-3 fatty acids.
  • Unsalted nuts and legumes: Provide potassium, magnesium, and fibre.
  • Whole grains: Improve vascular health through fibre and micronutrients.

These foods work by reducing arterial stiffness, improving blood vessel function, and supporting fluid balance in the body.

So, Is Salt Actually Bad for You?

Salt isn’t inherently harmful.

Our bodies need a small amount of sodium to function. The problem arises when intake exceeds healthy levels over time, particularly in the context of a poor diet and sedentary lifestyle.

The evidence is clear: high salt intake is a major risk factor for high blood pressure and related health issues (5). But it’s also one of the easiest risks to modify with small, consistent changes.

What To Do If Your Blood Pressure Is High

If your blood pressure is elevated, simple lifestyle adjustments can make a real difference:

In Summary

While salt is an essential nutrient, too much can quietly increase blood pressure and the risk of heart disease.

Fortunately, by becoming aware of hidden salt in foods and making small dietary changes, you can maintain blood pressure and heart health for the long term. It’s simpler than you think: eat more “real foods” and cut down on “processed foods.” 

Limiting processed foods also decreases the risk of obesity, diabetes, heart disease, and bowel cancer.

Salt and Blood Pressure: Frequently Asked Questions

  1. How does salt affect blood pressure?

Excess salt can raise blood pressure by causing your body to retain water, stiffening your blood vessels, causing inflammation, and altering gut microorganisms.

  1. Can stopping salt help lower blood pressure?

Lowering your salt intake is one of the best ways to reduce the risk of high blood pressure. If you or anyone you love has high blood pressure, a lower salt intake can help improve blood pressure.

  1. Which salt is good for high BP?

You might probably think sea salt or kosher salt is better, but you’re wrong. The amount of sodium in these salts and table salt is almost the same. It’s best to stick to the recommended daily amount, no matter which salt you take.

  1. What raises blood pressure quickly?

Besides the obvious culprits (salt, anger, and worry), other factors can raise your blood pressure quickly, such as:

  • Added sugar
  • Sleep issues like apnoea (repeated breathing pauses during sleep)
  • Acute pain
  • Nicotine from cigarettes and vapes
  • Alcohol consumption
  1. Is it safe to eliminate sodium and take a potassium supplement for better control of blood pressure?

No, this isn’t safe.

Your body needs a small amount of sodium to function normally. Eliminating sodium from your diet can lead to complications like low blood pressure. Always talk with your doctor before starting any supplement, including potassium supplements.

ALWAYS CONSULT A DOCTOR IF YOU HAVE ANY CONCERNS ABOUT BLOOD PRESSURE AND DIET.

References:

  1. “Blood Pressure Information – St Ives, Primary Care Network, Cambridgeshire.” St Ives, Primary Care Network, Cambridgeshire, www.stivespcn.nhs.uk/blood-pressure-information.
  2. Grillo, Andrea et al. “Sodium Intake and Hypertension.” Nutrients vol. 11,9 1970. 21 Aug. 2019, doi:10.3390/nu11091970
  3. Kim, Hack-Lyoung. “Arterial stiffness and hypertension.” Clinical hypertension vol. 29,1 31. 1 Dec. 2023, doi:10.1186/s40885-023-00258-1
  4. Smiljanec, Katarina, and Shannon L Lennon. “Sodium, hypertension, and the gut: does the gut microbiota go salty?.” American journal of physiology. Heart and circulatory physiology vol. 317,6 (2019): H1173-H1182. doi:10.1152/ajpheart.00312.2019
  5. Jama, Hamdi A., and Francine Z. Marques. “Don’t Take It With a Pinch of Salt.” Circulation Research, vol. 126, no. 7, Mar. 2020, pp. 854–56, doi:10.1161/circresaha.120.316816.
  6. Corliss, Julie. “Dietary Salt and Blood Pressure: A Complex Connection.” Harvard Health, 1 Mar. 2024, www.health.harvard.edu/heart-health/dietary-salt-and-blood-pressure-a-complex-connection.
  7. World Health Organization: WHO. Sodium Reduction. 7 Feb. 2025, www.who.int/news-room/fact-sheets/detail/sodium-reduction#.
  8. Public Health England. National Diet and Nutrition Survey. Assessment of salt intake from urinary sodium in adults (aged 19 to 64 years) in England, 2018 to 2019. https://assets.publishing.service.gov.uk/media/5e7cd9cdd3bf7f133ed1b6a1/Report_England_Sodium_Survey_2018-to-2019__3_.pdf
  9. Aburto, Nancy J et al. “Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses.” BMJ (Clinical research ed.) vol. 346 f1378. 3 Apr. 2013, doi:10.1136/bmj.f1378