Sodium, the Heart and Kidney Disease 

Today, the average sodium intake in an American diet is about 3,400 mg a day — 30 to 50 percent more than the recommended amount. And if you have chronic kidney disease (CKD) and consume too much sodium, you are at greater risk for complications, including high blood pressure and heart disease. One way to minimize these risks is to understand the role that sodium plays in balancing fluids in your body.

How are sodium, your heart and kidney disease connected? 

Sodium is an electrolyte (a mineral with an electric charge) that is needed for proper nerve and muscle function and it also helps balance the fluids in the body. However, when you have kidney disease and eat a salty diet, your kidneys cannot effectively remove excess sodium from your blood. This causes you to become thirsty, drink more and become overloaded with fluid because your kidneys’ inability to also remove excess fluid. As sodium and fluid builds up in your tissues and bloodstream, your blood pressure rises. High blood pressure (also called hypertension) can cause diseased kidneys to worsen. The heart is negatively affected by excess sodium in the body, too. With too much sodium in your bloodstream and elevated blood pressure, your heart must work harder, causing it to become weak and enlarged.

One way to protect your heart when you have kidney disease is to consume less sodium. Talk with your nephrologist and renal dietitian about the amount of sodium you should consume each day and whether you should limit your fluid intake.

Low-sodium diets

The USDA’s Dietary Guidelines for Americans 2010, released every five years, recently set new sodium goals. According to the 2010 guidelines, sodium should be limited to 2,300 mg a day. For people 51 years or older, African Americans and anyone who has hypertension, diabetes or CKD, the new sodium goal is 1,500 mg a day. About half of the United States’ population and the majority of adults fall into this category.

For people on dialysis, following a low-sodium diet can help control blood pressure and reduce the desire to drink too much liquid. Based on your doctor’s orders, your dietitian can help you devise a low-sodium diet that is tailored to your medical needs.

Ways to limit sodium

There are some steps you can take to limit the amount of sodium in the foods and beverages you consume:

  • Talk to your dietitian. Your dietitian can assist you in creating an eating plan that will help balance your sodium intake, and support kidney and heart health.
  • When grocery shopping, pay attention to food labels. Good choices are foods with labels containing the words:
    • Unsalted
    • Reduced-sodium
    • No salt added
    • Sodium-free
    • Low-sodium

For entrees, choose those with less than 400 mg of sodium per serving. For most other items, choose ones with less than 100 mg of sodium per serving.

  • When cooking, limit the amount of salt added to the foods you prepare or leave it out completely. Remove the salt shaker from your dining table and replace it with an herb seasoning blend for added flavor. As your taste buds adjust to the difference in flavor, you’ll find you won’t miss the added salt. You may even discover that you can detect saltiness, especially in restaurant and processed foods, and prefer lower sodium dishes.
  • Skip salt substitutes. Many contain a large amount of potassium as a replacement for sodium, which many people with CKD should avoid.
  • Eat less processed foods. Processed foods are typically high in sodium content. In fact, processed food accounts for about 90% of the sodium that Americans eat. Fortunately, some of the major food producers have committed to reducing sodium in their products to help people with the challenge of following a low-sodium diet. “Low sodium” foods often have potassium added. Be sure to check the nutrition label and avoid any foods with added potassium.


Kidneys do the important work of filtering your blood and maintaining proper chemical and fluid balance. But if you have kidney disease, excess fluid and sodium can build up in your bloodstream, leading to hypertension. Both fluid overload and high blood pressure puts a strain on your heart and can lead to serious heart problems. By working with your dietitian, you can find easy ways to reduce sodium and protect heart health when you have kidney disease.