Chronic kidney disease: What to know about this common, serious condition

Chronic kidney disease (CKD) is a serious health condition that affects about one in seven US adults. Understanding CKD, its risk factors, symptoms, and treatments can help people manage the condition effectively and prevent further complications.

What is chronic kidney disease?

Chronic kidney disease (CKD) develops when the kidneys are damaged and slowly lose their ability to work as they should. Healthy kidneys filter blood, remove waste, balance electrolytes, and help control blood pressure. When the kidneys are no longer able to filter waste and excess fluids from the blood properly, waste and fluids can build up, causing serious health issues.  CKD is a chronic disease because it usually progresses over time.

What are the main causes and risk factors of CKD?

The two most common causes of CKD are poorly controlled diabetes and high blood pressure. Over time these conditions damage and weaken the blood vessels in the kidneys, affecting their ability to function well.

Other types of kidney diseases can lead to CKD over time. For example, some people inherit kidney problems like polycystic kidney disease, where fluid-filled sacs (cysts) grow in the kidneys. These cysts take up space and disrupt kidney function, leading to gradual damage.

Several factors can increase the risk of developing CKD. Some of the most common risk factors include:

• Genetics and family history. CKD may run in families, so a family history of kidney disease can raise your risk. Being of a non-White ethnicity, such as Black American, Afro-Caribbean, Hispanic, or Asian (including South Asian and Pacific Islander), is also a risk factor.
• Age. Adults ages 65 years and older are more likely to develop CKD, as kidney function often declines naturally with age.
• Heart disease. Heart disease increases the risk for CKD because it reduces blood flow to the kidneys, which over time can damage kidney tissues and impair their function.
• Smoking. Smoking can contribute to CKD by damaging blood vessels and increasing your risk for blood clots, which reduces blood flow to the kidneys and makes them work less effectively over time.
• Obesity. Excess weight can put strain on the kidneys, lead to the development of type 2 diabetes, and increase inflammation in the body, increasing the risk of CKD.
• Medications. CKD has been linked with the overuse of nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil) and naproxen (Aleve). Certain blood pressure medications called angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs), which are first-line therapies for kidney disease due to diabetes as well as some other conditions, may also be harmful to the kidneys under certain conditions.

Symptoms and stages of chronic kidney disease

CKD is often called a "silent disease" because many people don't experience symptoms in the early stages. Symptoms may not appear until the kidneys are significantly damaged. Here are some symptoms that may develop as CKD progresses:

• fatigue and low energy levels
• swelling in the legs, feet, or ankles due to fluid retention
• shortness of breath caused by fluid buildup in the lungs
• frequent urination, especially at night
• poor appetite and weight loss
• nausea and vomiting
• itchy skin from waste buildup
• muscle cramps.

CKD is divided into five stages, with stage 1 being mild and stage 5 being the most severe. The stages are categorized based on glomerular filtration rate (GFR), a blood test that shows how well your kidneys are working:

• Stage 1: Kidney damage with normal or high kidney function. Few to no symptoms are present.
• Stage 2: Mild kidney function decline. Symptoms may still be mild or nonexistent.
• Stage 3: Moderate decline in kidney function. Symptoms like fatigue and swelling may become noticeable.
• Stage 4: Severe decrease in kidney function. More noticeable symptoms may appear, and treatment becomes essential to slow progression.
• Stage 5: Kidney failure. Dialysis or a kidney transplant is usually required to prevent death.

Treating chronic kidney disease

While CKD cannot be cured, treatments can slow its progression and reduce symptoms. Treatment focuses on managing the underlying causes and protecting kidney function. Common treatments include:

• Managing blood pressure. Blood pressure–lowering medications will be a part of your treatment plan, along with lifestyle changes such as heart-healthy eating, reducing sodium in your diet, staying active, and quitting smoking.
• Managing diabetes. If you have diabetes, controlling your blood sugar is crucial to slowing kidney damage. Keeping your A1C — which reflects your average blood glucose over three months — below 7% is better for kidney health. This may be achieved through medications, weight loss if needed, a diabetes-friendly diet, and regular physical activity.
• Medications to reduce complications. When the kidneys lose function, it can lead to issues with fluid and electrolyte balance, like fluid buildup or high potassium. Other problems may include anemia, fatigue, high cholesterol, and bone disease. People with CKD may need medicines to treat these conditions and reduce complications.
• Dialysis. In advanced stages of CKD, dialysis may be needed. Dialysis is a procedure that removes waste and excess fluid from the blood, mimicking kidney function. It can be done in a hospital, clinic, or at home, depending on the type.
• Kidney transplant. For people with end-stage kidney disease (stage 5), a kidney transplant may be an option. A successful transplant can greatly improve quality of life and remove the need for dialysis.

Eating right if you have chronic kidney disease

A healthy diet plays an essential role in managing CKD. Dietary changes can help reduce the kidneys' workload and minimize waste buildup. It can also help manage risk factors such as high blood pressure, diabetes, heart disease, and obesity.

The first step toward eating right for kidney disease is to reduce your sodium intake. Sodium, commonly found in salt and other packaged food products, can cause blood pressure to rise and lead to fluid retention. Experts suggest aiming for less than 2,000 milligrams per day. Some tips for limiting salt and sodium intake include:

• Choose fresh foods and cook from scratch when possible. Processed and restaurant foods usually contain added sodium.
• Use herbs, spices, or sodium-free seasonings instead of salt.
• Check food labels for sodium content — 20% or more of the Daily Value means it's high.
• Choose products labeled as "sodium-free," "low sodium," "unsalted," or "lightly salted."

Some other key dietary recommendations for people with CKD include:

• Limit protein intake. Eating too much protein can put extra strain on the kidneys. Work with a dietitian to reduce protein in your diet as needed.
• Limit potassium and phosphorus. Potassium and phosphorus are minerals that can build up in the body if kidney function is poor. Excess phosphorus in the blood can weaken bones by drawing out calcium, making them more fragile and prone to breaking. Too much potassium can cause serious heart problems. Foods high in potassium (such as bananas, oranges, and potatoes) and phosphorus (such as meat, poultry, fish, dairy products, and nuts) may need to be limited, especially in advanced stages of CKD.

Working with a registered dietitian who specializes in kidney disease can be very helpful in creating a personalized meal plan that supports kidney health.

Other lifestyle changes

In addition to diet and medications, making other lifestyle changes can help manage CKD. Physical activity can help manage blood pressure, improve heart health, and support healthy weight management, all important risk factors for CKD. The CDC recommends 150 minutes of moderate-intensity physical activity every week.

Here are some additional lifestyle changes that can help protect your kidney function and improve your overall health:

• Quit smoking. Smoking can worsen kidney damage and increase the risk of heart disease. Research has shown that the longer people stayed away from smoking, the lower their risk of worsening kidney problems.
• Limit alcohol intake. Drinking too much alcohol can raise blood pressure and harm the kidneys. Consult your healthcare provider to see if alcohol is safe for you. If so, keep it moderate: up to one or two drinks per day for men and one drink per day for women and adults over 65.
• Manage stress. Long-term stress can raise blood pressure and blood sugar, making kidney disease harder to manage. Activities like exercise, sleep, and relaxation techniques can help.
• Get regular check-ups. Seeing a doctor regularly allows for close monitoring of kidney function, as well as blood pressure and blood sugar levels. Early detection of changes can make it easier to adjust treatments if needed.

Living with CKD requires lifestyle adjustments and a commitment to managing health. With the right approach, people with CKD can improve their quality of life and slow the progression of kidney damage.