Kidney disease — consistent loss of kidney function — typically doesn’t cause symptoms when it starts. If you or someone you love is among the 37 million Americans diagnosed with chronic kidney disease (CKD), you’re likely curious as to whether that kidney damage is permanent.

While existing kidney damage usually can’t be reversed, there are ways to slow or even stop further damage. Depending on the cause and stage of your kidney disease, a nephrologist (kidney doctor) may suggest lifestyle changes and medications to help protect your kidneys and keep them working as well as possible.

Since kidney disease can be caused by various conditions, here’s a look at the possible causes and steps you can take to manage your kidney health.

What Is Chronic Kidney Disease?

Chronic kidney disease is a condition where the kidneys sustain damage or reduced function for at least three months. This damage is often progressive and, in many cases, irreversible, but early intervention may help slow or stop its progression. Damaged kidneys are unable to properly filter blood, which means toxins, waste, and excess water remain in the body. If the kidneys can’t remove these from the body, serious health issues can arise.

Kidney disease is broken down into disease stages. Your stage is determined by how efficiently your kidneys filter waste from blood. However, you may not have any symptoms until later stages, so kidney damage may go unnoticed in the early stages. Actually, as many as 9 out of 10 adults are unaware of their CKD until it is diagnosed by the doctor.

Kidney function can be assessed through blood and urine tests. Your estimated glomerular filtration rate (eGFR) measures how well your kidneys filter waste from blood. The ratio of urine albumin (a protein found in blood) and urine creatinine (waste product found in urine) detects the presence of kidney disease.

Stages and Symptoms of Chronic Kidney Disease

The five stages of kidney disease are:

• Stage 1 — Your eGFR is normal (score of 90 or above) but albumin is present in urine.
• Stage 2 — Your eGFR is 60-89 and shows kidneys are mildly damaged but still function well. Most people in this stage don’t have symptoms.
• Stage 3a — Your eGFR is 45-59 and shows mild to moderate kidney damage. Kidneys don’t function as well, symptoms are likely to begin.
• Stage 3b — Your eGFR is 30-44 and shows moderate kidney damage. Though kidneys are permanently damaged, proper management can stop progression to stages 4 and 5.
• Stage 4 — Your eGFR is 15-29 and shows severe kidney damage. Kidneys work poorly and waste buildup within the body can cause serious health conditions, such as stroke.
• Stage 5 — Your eGFR is below 15 and shows kidneys are close to failure or have failed (end-stage kidney disease). Dialysis or kidney transplant are necessary.

Symptoms of kidney disease that may be noticed around stage 3a include:

• Changes in frequency of urination (peeing more or less than usual)
• Itchy skin
• Pain in the flank (the area on either side of your abdomen, between your lower ribs and hips)
• Dark or foamy urine

Additional symptoms that may appear during stage 5 include:

• Skin rashes
• Loss of appetite
• Upset stomach
• Nausea
• Frothy or bubbly urine

Treating Stage 5 Chronic Kidney Disease

Stage 5 requires treatment with dialysis or kidney transplant.

Dialysis is a treatment that helps remove waste, extra fluid, and toxins from the blood when the kidneys can no longer do so effectively. It helps keep the body's balance of water, minerals, and electrolytes in check, preventing dangerous complications.

There are two kinds of dialysis:

• Hemodialysis — when blood is filtered through an artificial kidney machine — is typically done within a healthcare setting.
• Peritoneal dialysis — when a surgically inserted catheter (tube) delivers cleansing fluid to the body — is an option for home-based dialysis.

A kidney transplant is an operation in which a healthy kidney from a donor is placed into a person whose kidneys have failed. This new kidney takes over the job of filtering waste and excess fluid from the blood, reducing the need for dialysis. Kidney transplantation is often the preferred treatment for eligible patients with end-stage kidney disease, but wait times for a suitable donor can be long.

Causes of Chronic Kidney Disease and Why They Matter

Though there is no way to reverse existing kidney damage, there are steps you can take that may slow the progression of the disease. The best way to manage kidney disease will depend on the root cause. Some root causes are common — such as diabetes or hypertension (high blood pressure). Other times, rare kidney diseases are the cause.

Diabetes

Diabetes is the most common cause of chronic kidney disease and the No. 1 cause of kidney failure among Americans. It’s estimated that one-third of all people living with diabetes will end up with kidney disease. Among people with type 1 diabetes, at least half will develop some level of kidney damage. In addition, high blood pressure — the second most common cause of CKD — is often present in people with diabetes.

Diabetes causes kidney disease because high blood glucose (blood sugar) interferes with normal kidney function. Specifically, small blood vessels in the kidneys can become narrowed or clogged by high blood sugar. The impairment of renal (kidney) blood vessels results in kidney damage.

Managing kidney disease caused by diabetes requires controlling the underlying diabetes. Proper management of blood sugar can help to slow disease progression and preserve existing kidney function. Your healthcare provider may prescribe medications to manage your kidney disease and diabetes.

Since diabetes is the leading cause of kidney failure in the U.S., people with diabetes should get regular kidney screenings. Early detection and treatment can help prevent kidney disease from reaching advanced stages.

High Blood Pressure

High blood pressure is the second most common cause of chronic kidney disease. In the U.S., an estimated 20 percent of adults with high blood pressure may also have CKD.

High blood pressure can lead to kidney disease by narrowing and constricting the renal blood vessels. The kidneys are then unable to function properly, which causes fluid and waste to build up in the blood. Extra fluid in the blood can then elevate blood pressure, which is why high blood pressure is also a complication of kidney disease.

The first step in managing kidney problems caused by high blood pressure is bringing your blood pressure under control. This is usually done with medication, such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs), which help lower blood pressure and protect the kidneys. However, a healthy diet — low in sodium, processed foods, and excess protein, while rich in fruits, vegetables, and whole grains — can also help slow the progression of kidney disease.

In the United States, high blood pressure is one of the most common causes of kidney failure. Since both high blood pressure and early-stage CKD are often asymptomatic (have no symptoms), regular checkups with your healthcare provider are essential. Controlling your blood pressure can help slow kidney damage as well as help prevent end-stage kidney disease and the need for dialysis or kidney transplant.

Glomerular Disease

Glomerular disease is a condition that damages the glomeruli (small filters) of the kidneys. When glomeruli are damaged, they are unable to filter blood well. This can result in albumin being released through urine and waste buildup in the body.

Glomerular disease has many potential causes. Some are rare, while others, like lupus nephritis and IgA nephropathy, are more common. Diabetes primarily causes diabetic nephropathy, a separate condition affecting kidney function. Some other possible causes include:

• Immune complex membranoproliferative glomerulonephritis (IC-MPGN or MPGN)
• Lupus nephritis
• IgA neuropathy (Berger’s disease)
• Membranous nephropathy
• Goodpasture’s syndrome
• Minimal change disease (also called “nil disease”)

Some genetic disorders can also cause damage to the glomeruli. The most common genetic cause is polycystic kidney disease. Other genetic disorders that may lead to kidney disease by affecting the glomeruli, include:

• Complement 3 glomerulopathy (C3G)
• Nephrotic syndrome
• Atypical hemolytic uremic syndrome
• Focal segmental glomerulosclerosis
• APOL1-related kidney disease
• Atypical hemolytic uremic syndrome
• Fabry disease
• Alport syndrome

Certain bacterial and viral infections and medications may also affect the glomeruli causing kidney problems.

Management depends on the specific cause of your glomerular disease and how much your kidneys have been damaged.

Depending on the cause, treatment may resolve your glomerular disease either permanently or temporarily. However, in some cases, treatment may not be an option or may not work. In the absence of effective treatment, glomerular disease can lead to kidney disease.

Glomerular disease can lead to severe kidney damage in some cases. People who have developed kidney failure (stage 5 CKD) due to glomerular disease require dialysis or a kidney transplant.

Preserving Existing Kidney Function

Although kidney disease can’t be reversed, certain habits can help protect your remaining kidney function and slow its progression. Some key lifestyle changes include:

• Seeing your healthcare provider regularly to monitor your kidney health
• Eating a kidney-friendly diet, focusing on fresh fruits, vegetables, and unprocessed foods that limit salt, potassium, phosphorus, and protein while also supporting heart health
• Exercising regularly to maintain overall health
• Not smoking, as smoking can worsen kidney damage
• Maintaining a healthy weight for your body
• Avoiding medications that can harm the kidneys, such as certain nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen

Your healthcare provider may recommend some or all of these lifestyle changes to help preserve your existing kidney function.

Find Your Team

MyKidneyDiseaseTeam is the social network for people with rare kidney disease and their loved ones. On MyKidneyDiseaseTeam, members come together to ask questions, give advice, and share their stories with others who understand life with rare kidney disease.

How do you manage your rare kidney disease? What treatments or lifestyle changes have helped you preserve your existing kidney function? Comment below, or start a new conversation on your Activities page.