Your heart and your kidneys may seem like unlikely partners, but they accomplish more together than you think. If you’re living with heart disease, you’ll need to keep an eye on your kidney health. Studies show that heart failure raises the risk of kidney disease. The same applies to the opposite — kidney disease can also lead to heart failure.

In this article, we’ll discuss how the heart and kidneys are closely connected. We’ll also cover the basics of cardiorenal syndrome. This condition develops when damage to your heart or kidneys affects the other organ. By understanding how these two organs work together, you can better care for your health.

How Are the Heart and Kidneys Connected?

Your heart works 24/7, 365 days a year pumping blood throughout your body. This muscle sends oxygen-rich blood to your organs and tissues, providing needed nutrients. Oxygen-poor blood is pumped back to your lungs to exchange carbon dioxide.

If you’re living with heart failure, your heart isn’t pumping as well as it should. The muscle may become too weak or damaged, which stretches the heart walls. A bigger heart can’t properly squeeze to move blood out to the body. The lower chambers of the heart, called ventricles, are responsible for pumping. If the ventricles are too stiff, they can’t expand wide enough to fill with enough blood.

Any type of heart failure limits how much oxygen-rich blood reaches your organs. This increases your risk of organ damage — especially in the kidneys. These bean-shaped filtering powerhouses rely on delicate blood vessels to filter and clean your blood. They remove waste and extra water that’s no longer needed. The kidneys rely on a steady supply of blood to work properly. When the heart doesn’t pump enough blood, it can negatively affect the kidneys.

Can People With Heart Failure Develop Kidney Disease?

The National Kidney Foundation notes that people with heart failure are more likely to develop chronic kidney disease (CKD). This is because the kidneys don’t get enough blood flow.

Conversely, those living with CKD are also at risk of developing heart failure. In CKD, the kidneys don’t work well enough to filter extra fluid out. This leads to fluid buildup and raises your blood pressure.

Fluid buildup also affects people with heart failure. Because the heart can’t pump enough blood, extra fluid backs up into the lungs. It can also collect in the legs. You may also experience shortness of breath, swelling, and weight gain.

What Is Cardiorenal Syndrome?

Cardiorenal syndrome is a health disorder that affects your heart and kidneys. How well your heart works affects how well your kidneys work. The same idea applies to how your kidneys impact your heart health.

The Cleveland Clinic notes that simultaneous heart and kidney issues are common. Approximately 64 million people worldwide are living with heart failure. Of people with heart failure, up to 63 percent have kidney disease as well.

There are five types of cardiorenal syndrome. Each takes into account which organ was affected first and how long you’ve had your symptoms. “Chronic” refers to a long-term health issue, while “acute” refers to a sudden, serious issue. The types of cardiorenal syndrome are as follows:

• Type 1 — Your heart suddenly stops working properly, affecting your kidneys (both acute).
• Type 2 — Chronic heart problems affect your kidneys slowly over time.
• Type 3 — An acute kidney problem leads to acute heart failure.
• Type 4 — CKD leads to chronic heart problems like heart disease.
• Type 5 — Other diseases affect both the heart and kidneys.

How Does Cardiorenal Syndrome Develop?

Have you ever been asked the question, “Which came first — the chicken or the egg?” Doctors and researchers sometimes have the same problem when trying to figure out how cardiorenal syndrome develops. It can be hard for health care providers to figure out whether heart failure causes kidney problems or if it’s the other way around.

Problems that lead to cardiorenal syndrome include:

• Heart failure
• Kidney disease or a kidney injury
• Buildup of plaque inside your arteries
• Autoimmune diseases like lupus
• Blood clots in the lungs
• Diabetes

We know that heart failure and CKD share many risk factors. These same factors also play a role in cardiorenal disease, including:

• Diabetes
• Hypertension (high blood pressure)
• Having a body mass index (BMI) over 30

What Are the Symptoms of Cardiorenal Syndrome?

Cardiorenal syndrome affects both your heart and kidneys. You may experience symptoms related to your heart failure and/or CKD. Examples include:

• Swelling in your legs and abdomen
• Shortness of breath
• Fatigue or weakness
• Heart palpitations ( feeling like your heart skips a beat)
• Confusion
• Depression
• Making too little urine (pee)

How Do Doctors Diagnose Cardiorenal Syndrome?

If your doctor thinks you may have cardiorenal syndrome, they’ll order several tests. Many of these tests check your heart and kidney function. You’ll likely start with blood tests to measure your blood cell levels. A comprehensive metabolic panel (CMP) measures your blood sugar, electrolytes, and liver enzymes.

Urine tests look for the protein creatinine as a measure of kidney function. If your creatinine levels are higher than normal, you may have kidney damage. Creatinine levels also help doctors calculate the glomerular filtration rate (GFR). This measures how much blood your kidneys filter in a certain amount of time.

To check your heart function, your doctor may run an electrocardiogram (EKG). Also known as an ECG, this test measures your heart’s electrical activity. Your doctor may also order an echocardiogram or echo. This test uses sound waves to check how well your heart pumps.

How Do Doctors Treat Heart Failure and Kidney Problems?

Studies show that there isn’t one specific treatment that’s best for treating cardiorenal syndrome. Instead, your doctor will focus on treating your underlying heart failure and kidney problems.

Most people with cardiorenal syndrome have too much fluid in their bodies. Medications like diuretics help the kidneys clear out the fluid as urine. You may also hear diuretics referred to as “water pills.” Examples for treating cardiorenal syndrome include torsemide (Demadex) and furosemide (Lasix). People with cardiorenal syndrome often need to stay in the hospital to get medications that temporarily increase blood pressure and heart pump strength.

Long-term heart failure treatments focus on many things, like controlling high blood pressure and preventing heart scarring. Several medications relax the blood vessels, preventing extra strain on your heart and heart scarring. Examples include:

• Angiotensin II receptor blockers (ARBs), like valsartan (Diovan) and losartan (Cozaar)
• Beta-blockers, like metoprolol (Lopressor) and carvedilol (Coreg)
• ACE inhibitors, like lisinopril (Zestril) and enalapril (Vasotec)
• Angiotensin receptor plus neprilysin inhibitors (ARNIs), like sacubitril/valsartan (Entresto)

Your doctor may prescribe other medications for long-term heart failure treatment. These include:

• Aldosterone antagonists, like spironolactone (Aldactone) and eplerenone (Inspra)
• SGLT 2 inhibitors, like empagliflozin (Jardiance) and dapagliflozin (Farxiga)

If you have high cholesterol levels, statins may help manage them.

What Lifestyle Choices Help Manage Heart Failure and Kidney Disease?

A large part of treating heart failure and kidney disease is making healthy lifestyle choices. Eating a healthy diet and getting regular exercise helps control:

• Blood pressure levels
• Blood sugar levels
• Cholesterol levels
• Body weight

People with heart failure and kidney disease follow similar diets. A registered dietitian can make recommendations for what to eat and what to limit. You’ll likely need to focus on reducing your sodium intake. This helps keep your blood pressure levels in check.

By taking steps to address your heart and kidney issues, you’ll improve your outcomes. You’ll also preserve your heart and kidney function to prevent more organ damage. If you’d like to learn more about living healthy with heart failure and kidney disease, talk to your health care provider.

Talk With Others Who Understand

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Are you living with heart failure and kidney disease? How do you manage both conditions? Share your experience in the comments below or in a post on your Activities page.