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Understanding Blood Pressure

Category: Heart Health
Heart Health

Blood pressure measurements show the amount of work that your heart has to do to pump blood around your body. If the pressure inside your blood vessels is high and is left untreated, it will increase the risk of damage to the blood vessels in your heart muscle and other muscles in your body. This high pressure is also called hypertension. As a result this increases your risk of heart attacks and stroke as well as kidney, limb, eye and brain damage. Normal blood pressure should be close to 120/80mmHg. Acceptable target ranges can be different for some people, for example those with other medical conditions such as diabetes. Individualised targets can be discussed with your medical team.




High blood pressure is linked with a high level of salt in the food you eat. The more salt you eat, the more likely you are to retain fluid in your body. The salt acts like a sponge in your body soaking up liquid and retaining fluid. This extra fluid puts extra pressure on your heart to pump blood around your body, thus the more fluid you retain the higher your blood pressure will be.

It is estimated that each person in Ireland is consuming approximately 166% of the salt that they need per day.




Salt in very small amounts is essential to your health. A little salt is needed for maintaining water balance, healthy blood pressure and for healthy muscles and nerves. Too much salt in your diet will lead to high blood pressure.


Sources of salt in our foods:

  • Packet foods and eating out – 65-70%
  • Home cooking and at the table – 15-20%
  • Naturally in food – 15%




Salt can also be referred to on the nutrition information panels of food labels as Sodium rather than salt and this can be confusing. However, from December 2016 new European laws will require food producers to standardise this nutrition information, including listing the amount of salt in a product. See the INDI Food Labelling fact sheet for further information.

To work out how much salt is in a food, you need to multiply the sodium figure by 2.5. For example, if a food has one gram of sodium per 100g – that means it has 2.5 grams of salt.



How Do I Know if my Food Has Too Much Salt in it?

Check out the label, look at the per 100g section of the food stuff and follow the below guide.

Reading Amount of Salt per 100g
HIGH Over 1.5 grams
MEDIUM 0.3 grams to 1.5 grams
LOW  0.3 grams and under




Adults:            Between 4 and 6 grams of salt/day

Children:      School children - less than 4 grams/day, those younger should eat only the minimum amount of salt.




  • Try to remove the salt cellar from the table. This includes salt in all forms e.g. sea salt, rock salt, garlic salt.
  • When cooking, always taste food before you add any seasoning. Try freshly ground black pepper, herbs and spices instead of adding salt. If eating out ask for dressings or sauces to be served on the side rather than on the dish. This way you can control the amount you use.
  • Try to avoid the use of salt substitutes, these are not recommended together with certain heart medications and do not help us to adapt to a low salt diet.
  • Limit the use of stock cubes, gravy granules and ready-made sauces, which are all high in salt. Try making homemade stock or sauces instead. If needed compare sodium/salt content on a few different brands and opt for the lowest, a number of brands offer low salt alternatives.
  • Choose fresh vegetables and lean meat more often than tinned or processed varieties e.g. cured hams/bacon/rashers. If choosing tinned products e.g. fish opt for those tinned in fresh water, olive oil or lower salt varieties and rinse these products with water to remove excess salt. Try and use less jar and packet soups and sauces, try to make them from fresh at home and use less salt.
  • Cut down on salty snacks such as crisps, Bombay mix, salted nuts and other salty snacks.

Be patient. It will take a number of weeks to adapt to the lower salt content in your diet. When you start reducing your own salt intake, foods may taste a little bland at first. Gradually over about 6-8 weeks your taste buds will adjust and you will get used to less salty foods. Manufacturers have been reducing the salt content in the processed foods you eat over recent years by very small amounts so that consumers haven’t been able to notice the difference. The changes recommended here may be more dramatic and therefore more noticeable. However, making changes to your salt intake may help to improve your blood pressure.




Watch your Waistline

Being overweight or obese can increase your blood pressure also. Watching your portion sizes of food will also help maintain or even reduce your weight. It will also help to reduce your salt intake, especially if you reduce the portion size of high salt foods e.g. takeaways, frozen foods/ ready meals e.g. pizzas, ready meals. Losing weight – even as little as 5-10% of your starting weight – will help. For more information on losing weight refer to the (weight loss factsheets) and



Too much alcohol is known to increase blood pressure. If you do enjoy a drink ensure you are within low risk limits set out in Ireland;

  • Men – Maximum of 17 standard drinks per week
  • Women – Maximum of 11 standard drinks per week
  • 2 alcohol free days per week


What is a Standard Drink?

1/2 pint of beer/stout/larger/cider

A pub measure of spirits (35.5ml)

100ml glass of wine (12% alcohol)



Being physically active is one of the most important things you can do to reduce your blood pressure. Try to build more physical activity into your lifestyle aiming for at least 30 minutes of moderate intensity activity on five or more days of the week. This can be broken up into segments of 10-15 minutes. Remember to check first with your doctor if you have heart problems or are new to exercise.



Drinking a lot of caffeine can raise blood pressure. If you drink a lot of coffee, tea (including green tea) energy drinks and cola drinks you should try cutting down. Diet fizzy drinks have the same caffeine content; try sparkling water instead with squash.

Aim for no more than 3-4 cups of tea or coffee per day.




Taking dietary supplements such as calcium, magnesium and potassium is not recommended for reducing blood pressure. There are no alterative diet therapies or supplements that can be recommended to control blood pressure and the changes outlined here are not replacements for prescribed medication. Making lifestyle changes e.g. reducing the salt content, reducing weight and taking regular exercise may have significant beneficial effects on your blood pressure. These changes may reduce your need for medication in time but any changes should be made under the supervision of your doctor. 




Created by the Cardiology Interest Group, July 2016. Review date July 2019

© 2016 Irish Nutrition and Dietetics Institute, INDI. All rights reserved. May be reproduced in its entirety provided source is acknowledged. This information is not meant to replace advice from your medical doctor or individual counselling with a dietitian. It is intended for educational and informational purposes only.




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