Chronic kidney disease, often called CKD, is a long-term condition in which the kidneys gradually lose their ability to filter waste and excess fluid from the blood. Because kidney damage can develop slowly, many people do not notice symptoms during the early stages.
The kidneys also help regulate blood pressure, balance minerals, support red blood cell production, and maintain fluid levels. When kidney function declines, these important processes can become affected.
Early testing, appropriate treatment, and daily lifestyle changes may help slow chronic kidney disease progression and reduce the risk of kidney failure.
What Is Chronic Kidney Disease?
Chronic kidney disease occurs when the kidneys remain damaged or function below normal for at least three months. Kidney damage may be detected through blood tests, urine tests, imaging, or other medical evaluations.
The two main measurements used to assess kidney health are:
Estimated glomerular filtration rate (eGFR): Estimates how well the kidneys filter blood.
Urine albumin-to-creatinine ratio (UACR): Measures the amount of albumin, a type of protein, in the urine.
Healthy kidneys usually keep most protein in the blood. When kidney filters are damaged, protein may leak into the urine. This condition is known as albuminuria.
Kidney Disease Symptoms
Kidney disease symptoms depend on how much kidney function has been lost. Early CKD may cause no noticeable symptoms at all.
As the condition progresses, possible symptoms include:
Tiredness or persistent fatigue
Swelling in the feet, ankles, hands, or around the eyes
Changes in urination frequency
Foamy or bubbly urine
Blood in the urine
Increased nighttime urination
Dry or itchy skin
Muscle cramps
Poor appetite
Nausea
Trouble concentrating
Sleep problems
Shortness of breath
High blood pressure
Many of these symptoms can also occur with other health conditions. For this reason, symptoms alone cannot confirm kidney disease. Blood and urine testing are often necessary.
Early Signs of Chronic Kidney Disease
The early signs of chronic kidney disease may be subtle or absent. Possible clues include:
Elevated blood pressure
Protein in the urine
Blood in the urine
Abnormal creatinine levels
A reduced eGFR
Mild fatigue
Changes in urination
People with diabetes, high blood pressure, heart disease, or a family history of kidney disease may need regular kidney screening even if they feel well.
What Causes Chronic Kidney Disease?
The most common chronic kidney disease causes in adults are diabetes and high blood pressure.
Diabetes and Kidney Disease
High blood sugar can damage the tiny blood vessels and filtering structures in the kidneys. Over time, this damage may cause albumin to leak into the urine and reduce kidney function.
This is why people with diabetes may need routine urine albumin and kidney function testing.
High Blood Pressure and Kidney Disease
High blood pressure places extra pressure on the blood vessels inside the kidneys. Damaged kidneys may also make blood pressure more difficult to control, creating a cycle in which each condition worsens the other.
Other Causes
Other causes of chronic kidney disease include:
Polycystic kidney disease
Glomerulonephritis
Repeated kidney infections
Kidney stones that cause long-term obstruction
Lupus and other autoimmune diseases
Congenital kidney abnormalities
Long-term use of certain medications
Blockages in the urinary tract
Inherited kidney conditions
Chronic Kidney Disease Risk Factors
Your risk of CKD may be higher if you have:
Diabetes
High blood pressure
Heart disease
A family history of kidney disease
Previous acute kidney injury
Obesity
Smoking history
Recurrent kidney infections
Kidney stones
Older age
Long-term exposure to medications that may affect the kidneys
If you have one or more risk factors, ask your healthcare professional whether regular kidney disease blood tests are appropriate.
Chronic Kidney Disease Stages
The chronic kidney disease stages are mainly classified according to eGFR. The stages help healthcare professionals understand kidney function and determine the appropriate monitoring and treatment.
CKD StageeGFR RangeGeneral MeaningStage 190 or higherKidney damage may be present, but filtration is normal or near normalStage 260–89Mild reduction in kidney functionStage 3a45–59Mild to moderate reductionStage 3b30–44Moderate to severe reductionStage 415–29Severe reduction in kidney functionStage 5Below 15Kidney failure or severely reduced kidney function
A person is not classified only by eGFR. Doctors also consider urine albumin levels, symptoms, imaging results, and whether the abnormal findings remain present for at least three months.
Kidney Disease Stage 1 and Stage 2
People with kidney disease stage 1 or stage 2 may feel completely normal. Treatment usually focuses on controlling the underlying cause, protecting kidney function, and reducing cardiovascular risk.
Stage 3 Chronic Kidney Disease
Stage 3 chronic kidney disease may be divided into stage 3a and stage 3b. Some people begin to experience fatigue, swelling, changes in urination, or anemia, although symptoms vary.
Regular monitoring becomes increasingly important during this stage.
Kidney Disease Stage 4
Kidney disease stage 4 indicates a severe reduction in kidney function. Symptoms may become more noticeable, and complications such as anemia, mineral imbalance, high potassium, and fluid retention may develop.
At this stage, a nephrologist may discuss treatment planning and preparation for possible kidney replacement therapy.
Kidney Disease Stage 5
Kidney disease stage 5 is also known as kidney failure. The kidneys are no longer able to adequately remove waste and excess fluid from the body.
Treatment may involve dialysis, kidney transplantation, or conservative kidney care, depending on the person’s medical condition, preferences, and treatment goals.
How Is Chronic Kidney Disease Diagnosed?
A chronic kidney disease diagnosis usually involves more than one test.
Common evaluations include:
Serum creatinine blood test
eGFR calculation
Urine albumin-to-creatinine ratio
Urinalysis
Blood pressure measurement
Kidney ultrasound
CT scan or MRI when needed
Additional blood tests
Kidney biopsy in selected cases
A single abnormal result does not always mean a person has chronic kidney disease. Repeat testing may be needed to determine whether the problem is persistent.
Kidney Disease Blood Test
A common blood test for kidney disease checks creatinine level. Creatinine is a waste product of muscle metabolism that your kidneys normally filter out. If kidney function is limited, creatinine levels may increase.
Apart from that, the creatinine level can reflect a person's muscle mass, water level, medicines or other variables. Healthcare providers consider creatinine level and eGFR and other test results for a complete picture.
Chronic Kidney Disease Treatment
The goal of chronic kidney disease treatment is to slow further damage, manage symptoms, and reduce complications.
Treatment depends on the cause and stage of CKD.
Managing Blood Pressure
Keeping blood pressure within the recommended range can help protect the kidneys. Doctors may prescribe medications such as ACE inhibitors or angiotensin receptor blockers, particularly when albuminuria is present.
Managing Blood Sugar
For people with diabetes, controlling blood sugar can reduce the risk of further kidney damage. Some diabetes medications may also provide kidney or cardiovascular benefits, depending on the individual’s health.
Managing Cholesterol
High cholesterol can increase cardiovascular risk. A healthcare professional may recommend dietary changes, exercise, and cholesterol-lowering medication when appropriate.
Chronic Kidney Disease Medications
Depending on the condition, chronic kidney disease medications may include:
Blood pressure medicines
Diabetes medications
Cholesterol-lowering medicines
Diuretics for fluid retention
Iron supplements or other treatments for anemia
Medicines to manage high phosphate levels
Treatments for abnormal calcium or parathyroid hormone levels
Sodium bicarbonate for selected patients with metabolic acidosis
Medication choices should be individualized. Some over-the-counter pain relievers, particularly frequent or long-term NSAID use, may worsen kidney function in certain people.
Chronic Kidney Disease Diet
A chronic kidney disease diet should be based on kidney function, blood test results, medications, and other health conditions. There is no single diet that is appropriate for every person with CKD.
Depending on the stage of disease, a dietitian may recommend adjustments to:
Sodium
Protein
Potassium
Phosphorus
Fluid intake
Calories
Carbohydrates
Best Foods for Kidney Disease
Many people with CKD can include:
Fresh fruits and vegetables in portions suited to their potassium needs
Whole grains when appropriate
Unsalted foods
Lean proteins
Fish
Eggs
Healthy fats
Home-prepared meals with limited sodium
Foods to Avoid With Chronic Kidney Disease
Depending on laboratory results and medical advice, people may need to limit:
Highly processed foods
Packaged soups
Fast food
Processed meats
Foods high in sodium
Certain high-potassium foods
Foods containing phosphate additives
Excessive sugary drinks
Do not make major potassium, protein, or fluid restrictions without professional guidance. Restricting the wrong nutrients can create additional health problems.
How to Improve Kidney Function
Many people ask how to improve kidney function or how to lower creatinine. The answer depends on why kidney function is abnormal.
Helpful steps may include:
Controlling blood pressure
Managing diabetes
Drinking the amount of fluid recommended by your healthcare professional
Avoiding unnecessary NSAID use
Taking prescribed medications correctly
Treating urinary infections promptly
Maintaining a healthy weight
Following an individualized kidney-friendly diet
Avoiding tobacco
Getting regular kidney function tests
If creatinine rises because of dehydration, medication effects, infection, or another temporary problem, it may improve after the cause is treated. However, chronic kidney damage cannot always be reversed.
Can Chronic Kidney Disease Be Reversed?
This largely depends on a number of factors including the cause and severity of CKD. For some kidney conditions the damage can be reversed if the root cause is eliminated. In contrast, chronic kidney damage that causes structural changes is hardly reversible.
If the kidney health does not normalize completely through treatment, chronic kidney disease can be slowed down by medication, and kidney failure may be prevented for some time.
Chronic Kidney Disease Complications
As CKD progresses, possible complications include:
High blood pressure
Anemia
Bone and mineral disorders
High potassium
Fluid retention
Heart disease
Nerve problems
Sleep difficulties
Malnutrition
Metabolic acidosis
Kidney failure
CKD is closely connected to cardiovascular health. People with kidney disease have an increased risk of heart attack, stroke, and heart failure, making blood pressure and cholesterol management especially important.
Chronic Kidney Disease Dialysis and Transplant
When kidney function becomes severely reduced, some people may need dialysis. Dialysis helps remove waste and excess fluid from the blood when the kidneys can no longer do this adequately.
The two main types are:
Hemodialysis
Peritoneal dialysis
A kidney transplant for chronic kidney disease may be an option for selected patients with kidney failure. Transplant evaluation often begins before dialysis is required, when possible.
Some people may instead choose conservative kidney care, which focuses on symptom relief, comfort, and quality of life without dialysis or transplantation.
How to Manage Chronic Kidney Disease
Long-term chronic kidney disease management may include:
Keeping medical appointments
Monitoring blood pressure
Completing recommended blood and urine tests
Taking medications consistently
Following dietary guidance
Staying physically active within safe limits
Avoiding smoking
Reporting new symptoms promptly
Discussing medication changes before taking new products
Working with a primary care professional and nephrologist when needed
When to Seek Medical Care
Contact a healthcare professional if you notice:
New or worsening swelling
Foamy or bloody urine
Significant changes in urination
Persistent nausea
Increasing fatigue
New shortness of breath
Uncontrolled blood pressure
Rapid weight gain from fluid retention
Seek emergency care for severe shortness of breath, chest pain, confusion, fainting, or sudden severe weakness.
Final Thoughts
Chronic kidney disease may take quite some time to reveal itself, often without symptoms. So, for individuals having diabetes, high blood pressure or other risk factors, getting tested early is highly recommended. It is vital that one knows about kidney disease symptoms, stages of CKD, diagnosis, treatment, and diet to be able to respond before the problem has worsened severely.
Speak to an appropriately educated doctor if kidney disease symptoms or risk factors persist. Kidney function or urine tests can be part of the discussion.