Ask the expert: Dr. Ennis on chronic kidney disease

The kidneys are vital organs that keep us healthy. They’re responsible for filtering waste products and excess fluids from the blood, which are then removed from the body through urine. Additionally, the kidneys help regulate blood pressure, balance electrolytes such as sodium and potassium, and produce hormones that are essential for red blood cell production and bone health.

When the kidneys don’t work properly, waste products and fluids can build up in the body, leading to symptoms such as swelling, fatigue and difficulty concentrating. This condition is known as chronic kidney disease (CKD), which can progress to kidney failure if not managed appropriately. CKD is often silent in its early stages, meaning many people are unaware they have it until significant damage has occurred. 

While anyone can develop CKD, certain factors increase the risk. The most common risk factors include:

• Diabetes: High blood sugar levels can damage the kidneys over time
• Hypertension (high blood pressure): Increased pressure can harm kidney blood vessels
• Cardiovascular disease: Heart conditions are linked to kidney problems
• Older age: Kidney function naturally declines with age
• Obesity: Excess weight can strain the kidneys
• Family history: A family history of kidney disease increases risk
• Ethnicity: African American, Native American and Hispanic individuals are at higher risk
• Other factors: Conditions like previous kidney injury, preeclampsia and certain genetic factors may increase risk of kidney disease

Understanding these risk factors and maintaining a healthy lifestyle can help protect kidney health. Regular check-ups and early detection are key to preventing and managing kidney disease effectively. If you think you may be at risk, talk to your primary healthcare provider to see if a kidney health test is right for you.

To help you learn more about CKD and kidney function, we sat down with Dr. Jennifer Ennis, MD, a medical director at Labcorp and nephrologist at the University of Illinois Medical Center, who answered your top questions about kidney health.

What happens to kidney function as you age?

“As we get older, our kidneys go through several changes that can affect how well they work,” explains Dr. Ennis.

One of the main changes is a decrease in the kidneys' ability to filter blood. This is assessed by the estimated glomerular filtration rate (eGFR), which tends to go down with age. We also lose some nephrons, the tiny filtering units of the kidneys, as we get older, which means the kidneys have fewer units to help them function well.

“Aging kidneys can also develop scarring (glomerular sclerosis) and shrinkage of the kidney tubules (tubular atrophy),” adds Dr. Ennis. “These changes make it harder for the kidneys to work properly.”

All these changes make older adults more susceptible to acute kidney injury (AKI) and chronic kidney disease. AKI is a sudden loss of kidney function, while CKD is a gradual decline over time. Regular check-ups and following medical advice are important to maintain kidney function and overall health.

What are early signs of kidney disease?

Symptoms of kidney disease may include frequent urination, swelling of ankles and feet and fatigue.

“However, kidney disease often has no symptoms in its early stages,” says Dr. Ennis. “That’s why early detection through routine blood and urine tests is critical for patients at risk.”

Other symptoms that may occur in later stages of kidney disease include difficulty concentrating, sleep problems, dry and itchy skin, poor appetite and muscle cramping.

Can kidney disease be inherited? 

Yes, some kidney diseases can be passed down from parents to their children through genes. If you have a family history of kidney disease, it’s important to talk to your healthcare provider, who may recommend genetic testing to see if you have inherited any of these gene changes. Early detection and management can help protect your kidney health and provide valuable information for your family members.

I have high blood pressure; do I need to worry about kidney disease?

High blood pressure (hypertension) is a common condition that can have serious implications for kidney health, as it can damage the blood vessels in the kidneys and reduce their ability to function properly. Over time, this can lead to CKD.

“Conversely, kidney disease can also cause high blood pressure by affecting the balance of salt and water in the body, activating certain hormones, and other pathways,” explains Dr. Ennis. “Regular monitoring of blood pressure and kidney function is essential. If you have high blood pressure, it's important to discuss your risk of kidney disease with your healthcare provider. Early detection and management can help protect your kidneys and overall health.”

Are there other common health conditions related to kidney disease?

CKD can be associated with several health concerns. Here are some common conditions related to CKD: 

• Diabetes: Diabetes, especially Type 2, is a major cause of CKD. High blood sugar levels can damage the kidneys, leading to a condition called diabetic nephropathy 
• Obesity: Obesity is a risk factor for CKD and can worsen other conditions that contribute to CKD, such as high blood pressure and type 2 diabetes
• Heart disease: People with CKD are at a higher risk of heart problems, including heart attacks, heart failure and irregular heartbeats. Heart disease is the leading cause of death in patients with CKD
• Anemia: CKD can cause anemia, a condition where you have fewer red blood cells than normal. This happens because the kidneys produce less of a hormone called erythropoietin, which helps make red blood cells
• Bone and mineral disorders: CKD can lead to problems with certain minerals in your blood, such as calcium and phosphorus. This can cause weak bones and other issues
• Electrolyte imbalances: Since CKD can cause imbalances in important minerals in your blood, like potassium and sodium, this may affect your heart and muscles
• Infections: People with CKD are more likely to get infections because their immune system is not as strong 

"Managing these conditions is crucial to improving quality of life for people with CKD,” says Dr. Ennis. “Regular check-ups and following your healthcare provider’s advice can help manage these health issues effectively.”

Is it possible to improve your kidney function once you have CKD?

If you have CKD, some strategies that can help improve or stabilize your kidney function include:

• Healthy nutrition: Incorporating plant-based foods and healthy fats while limiting sodium and ultra-processed foods in your diet can help slow CKD progression
  
• Regular exercise: Exercise can help lower blood pressure, control weight and protect heart health, all of which can benefit your kidneys
  
• Medication: Certain medications can have anti-inflammatory effects and reduce pressure inside the kidneys
  
• Managing related chronic conditions: If you have diabetes, high blood pressure or other related health conditions, managing them well can help protect your kidneys

What can I do to protect my kidney health and prevent kidney disease?

Protecting your kidney health is important, especially if you have high blood pressure or diabetes. Here are some simple steps you can take to keep your kidneys healthy: 

• Manage your blood pressure: Blood pressure control is crucial to help slow down the progression of kidney disease and reduce heart health risk
  
• Control your blood sugar: If you have diabetes, work with your provider to keep your blood sugar within the target range
  
• Eat a healthy diet: Incorporate more plant-based foods into your diet while limiting animal products and avoiding ultra-processed foods. These dietary changes can contribute to reduced inflammation and improve kidney function 
  
• Stay active: Aim for at least 30 minutes of exercise most days of the week to help maintain a healthy weight and improve overall health
  
• Quit smoking: Smoking can worsen kidney disease and increase the risk of heart problems. If you smoke, seek help to quit

Remember to talk to your healthcare provider before making any major changes to your diet or lifestyle.

What foods can help promote kidney health?

Eating the right foods can help keep your kidneys healthy, especially if you have high blood pressure, and may help slow down the progression of CKD in some individuals.

Dr. Ennis recommends incorporating more plant-based foods like fruits, vegetables, whole grains, beans, nuts and seeds, which can help lower blood pressure and improve kidney function.  “Diets like the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) are great examples,” she says.

Opt for whole, unprocessed foods, and use healthy fats like olive oil, flaxseed oil and canola oil to support heart health and reduce inflammation. Moderate your protein consumption (i.e., aim for about 0.8 grams per kilogram of body weight daily), as excessive protein can strain the kidneys, and avoid ultra-processed foods that are high in unhealthy fats, sugars and salt.

Additionally, if you have advanced kidney disease, work with your healthcare provider to manage your potassium intake.

“While these dietary tips are a helpful starting point to manage your blood pressure and protect your kidneys, always talk to your healthcare provider or a registered dietitian before making any major changes to your diet,” says Dr. Ennis.

How often should I get my kidneys checked?

All adults should get a yearly metabolic blood test, especially those with kidney disease risk factors. This helps you better understand both your overall health and kidney function. Your healthcare provider may also order urine testing or radiology tests based on your history, risk factors or other test results. 

What tests are used to check kidney health?

There are several tests that clinicians use to check how well your kidneys are working. The two primary tests used to assess kidney health are: 

• Glomerular filtration rate (GFR) test: This blood test estimates how well your kidneys are filtering waste from your blood by measuring a waste product called creatinine. Your creatinine level, along with your age and sex, are used to calculate your estimated GFR (eGFR). A lower eGFR means your kidneys are not working as well as they should
• Urine albumin-to-creatinine ratio (UACR): This test measures the amount of albumin (a type of protein) in your urine. Normally, your kidneys should not let much albumin pass into your urine. A high level of albumin in your urine can be an early sign of kidney damage

“These tests help physicians understand how well your kidneys are functioning and can detect early signs of kidney disease,” explains Dr. Ennis.

If you have any concerns about your kidney health, talk to your healthcare provider about these tests. 

How can I be proactive about my overall metabolic health?

Kidney health and metabolic health are often connected; cardiovascular-kidney-metabolic (CKM) syndrome is a health condition that is characterized by the links between heart disease, kidney disease, obesity and Type 2 diabetes.

There are several steps you can take to lower your risk of heart disease and other related health problems like kidney disease and diabetes. The American Heart Association and the American College of Cardiology provide the following recommendations to help achieve a healthy lifestyle and lower cardiovascular risk:

• Healthy diet: Eat plenty of vegetables, fruits, nuts, whole grains, lean proteins and fish. Try to avoid trans fats, red and processed meats, refined carbohydrates and sugary drinks
• Physical activity: Aim for at least 150 minutes of moderate exercise, like brisk walking, or 75 minutes of vigorous exercise, like running, each week 
• Weight management: If you are overweight, consider seeking advice on how to reduce your calorie intake and maintain a healthy weight
• Tobacco use: Avoid using tobacco products. If you smoke, seek help to quit
• Diabetes management: If you have Type 2 diabetes, focus on healthy eating and regular exercise. Your provider may recommend certain medications to help control your blood sugar and reduce your cardiometabolic risk 
• Regular check-ups: Adults aged 40 to 75 should have their heart disease risk assessed regularly. Discuss with your provider whether you need medications to manage your risk
• Team-based care: Work with a healthcare team to address all aspects of your health, including social factors that might affect your ability to stay healthy

By following these guidelines, you can significantly reduce your risk of heart disease and improve your overall health. 

How do I know if I should see my primary care provider (PCP) vs a specialist?

Your PCP may decide to refer you to a specialist in certain circumstances where your health conditions are difficult to control, or if you have multiple risk factors that require a team-based approach to manage your health most effectively.

Take control of your kidney health

Early detection is key when it comes to CKD. Screening measures like Labcorp OnDemand’s Kidney Health Test can help uncover signs of possible kidney disease or damage and provide a better understanding of overall kidney health. Your healthcare provider can help you determine whether a kidney health test is right for you, support you in interpreting your results and guide you through any next steps that may be needed.