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Why Doctors Limit Your Sodium Intake

For those who have heart failure, kidney disease, hypertension, and edema, you may have heard your doctor talk about reducing your sodium intake. This can be hard! Lots of food, especially premade or packaged, are high in sodium! It is even harder to implement this diet when you don’t fully understand why your doctor advises you to avoid these foods.

I am here to explain what sodium is, what sodium does in the body, and why if you have heart failure, hypertension, edema, or kidney disease, your doctor may be telling you to avoid sodium.

Sodium is not all bad, but if you have heart failure, hypertension, edema, or kidney disease sodium can cause issues.

Before we get too deep into this chat, let's first talk about what sodium even is. Sodium is a mineral that can be found in most foods.1 You can find how much sodium is in your food by checking the nutrition label on the back (see image below). 

Sodium content in Progresso soup
The Sodium content in Progresso Tomato Soup

Salt contains sodium chloride, so often these two terms are used interchangeably.1 Sodium is not all bad, but if you have heart failure, hypertension, edema, or kidney disease sodium can cause issues.


In a healthy body, sodium helps to balance the fluids between the inside of your cells and the outside of your cells. Sodium can help to increase your heart rate, provide electrolytes, and can also help your body send its chemical signals better; this is helpful for muscle and nerve functions.1 Sodium is like a magnet for water though. Too much sodium can cause your body to hold onto a lot of water. Your body does this because it is trying to dilute the sodium concentration either inside or outside of your cells. But if you have heart failure, hypertension, edema, or kidney disease this can cause your body to become overloaded with fluid and increase your blood pressure.

Heart failure, Hypertension and Edema

For those living with Heart Failure, monitoring your blood pressure is important. For the average adult, it is recommended that your resting heart rate falls between 60-100bpm (heartbeats per minute).At the end of this post I have linked the American Heart Association if you would like to calculate where your resting heart rate should fall. If you have Heart Failure, it is important to maintain a lower blood pressure. Maintaining lower blood pressure is important because it does not overwork the heart muscles.

In the case of Heart Failure, your heart muscle is really weak. It either cannot pump enough blood out into your body or your heart cannot fill up with enough blood.3 If you have Left-Sided Heart Failure, your body is not getting enough oxygen-rich blood. This may cause you to feel tired and it can also increase your blood pressure - known as Hypertension. If you have the type of Heart Failure that increases your blood pressure, fluid is being forced out of your blood and into your lungs. This is why you may notice you are short of breath or have a deep congested cough.

If you have Right-Sided Heart Failure, your heart is not able to squeeze hard enough to get all of the blood inside of your heart out into your lungs to deliver the oxygen it is carrying. This can lead to a backup of blood in your veins (kind of like slow-moving traffic). With this backup, Edema can occur. Edema is the build-up of fluid in your veins and tissues, making body parts like your legs, feet, ankles, or hands look swollen and puffy. 

Without getting too complicated in the science, sodium can both increase your blood pressure worsening Heart Failure and Hypertension, and increase the amount of fluid your blood is carrying leading to Edema.

Chronic Kidney Disease

Your kidneys work to filter and clean your blood. As blood moves through your body, it picks up extra fluid, toxins, and waste that is circulating throughout your body. As the blood passes through the kidneys, it is cleaned of the extra fluid, toxins, and waste that the blood has picked up. The kidneys can also remove excess nutrients (including sodium, sugar, and any unneeded vitamins). All of these toxins and excess nutrients are then removed from the body via your urine. In the case of Kidney Disease, toxins and excess sodium among other nutrients are not being removed properly. The inability to properly remove the excess sodium can increase your blood pressure. As we have learned, high blood pressure (also called Hypertension) can damage your heart, and your blood vessels and can further cause Edema

What You Can Do

Yes, your doctor may be telling you to limit your sodium intake but don’t fret! 

Many food companies are aware of the impact sodium can have on your health. Learn to check the nutrition label and look out for foods that say “low sodium” or “no added sodium”. 

Reduced sodium Progresso tomato soup
Example of canned soup with the label "Reduced Sodium"

In general, the FDA recommends consuming less than 2,300mg of sodium a day. If you have one of the diseases that we talked about today, it may be smart to keep a log. This log may include your sodium intake for each meal and any symptoms you are feeling that day such as: 

  • Feeling tired

  • Having a deep congested cough

  • Feeling extra thirsty

  • Or noticing swelling in your hands, feet, legs, or ankles. 

This log can be very helpful for your doctors and can assist them if you are ever having an emergency. 

Foods and Ingredients that contain sodium:

  • Baking soda

  • Salt

  • Fast foods

  • Frozen premade meals

  • Canned Soup

  • Canned Vegetables

  • Chips

  • Pretzels

  • Cheese

  • Lunch Meat

Low Sodium Alternatives:

  • Fresh or Frozen Vegetables

  • Canned soups with the label “low sodium” or “no added sodium”

  • Homemade meals

  • Unsalted pretzels

  • Unsalted chips

  • Reduced sodium lunch meats


  • Heart Failure- weakening of the heart muscles causing your ventricles to not fill with enough blood or pump enough blood out 

  • Hypertension- High blood pressure

  • Edema-  the build-up of fluid in your veins

  • Chronic Kidney Disease- a condition where the kidneys have been damaged and are no longer able to filter blood effectively 

Extra Links: 


  1. Gordon B. Is sodium the same thing as salt? Academy of Nutrition and Dietetics. Published August 8, 2019. Accessed February 2, 2024. 

  2. Target heart rate. American Heart Association. Published March 9, 2021. Accessed February 2, 2024. 

  3. Effects of congestive heart failure. Nucleus Medical Media. Published June 13, 2014. Accessed February 2, 2024. 


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