Chronic Kidney Disease: What It Is, Its 5 Stages, Causes, and How It's Treated
Updated: 6 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
TL;DR
Chronic kidney disease (CKD) is progressive kidney damage that lasts more than a few months. It affects about 1 in 7 American adults, and most don't know they have it because early stages have no symptoms. It is staged 1 through 5 using the eGFR blood test. Diabetes and high blood pressure are the top causes. There is no cure, but treatment can slow the damage and manage complications. End-stage kidney disease requires dialysis or a transplant to survive.
Quick Answer
Chronic kidney disease is long-term damage to the kidneys that slowly reduces their ability to filter blood. Most people have no symptoms until later stages. It is diagnosed with blood and urine tests and staged using the eGFR. Treatment focuses on slowing damage and managing complications, and when the kidneys fail, dialysis or a kidney transplant is needed. [1]
What the research says
CKD is common worldwide. A meta-analysis of 100 studies covering 6,908,440 people estimated a global CKD prevalence of 13.4% (95% CI 11.7% to 15.1%), including 10.6% for stages 3 to 5; stage 3 was the most common, at 7.6% (Hill et al., PLoS One, 2016) [3].
SGLT2 inhibitors slow kidney damage, with or without diabetes. A collaborative meta-analysis of 13 large placebo-controlled trials (90,413 participants) found that SGLT2 inhibitors reduced the risk of kidney disease progression by 37% (relative risk 0.63, 95% CI 0.58 to 0.69) and acute kidney injury by 23%, with similar effects in people with and without diabetes (SGLT2 Inhibitor Meta-Analysis Cardio-Renal Trialists' Consortium, Lancet, 202202074-8)) [4].
Depression is common in CKD. A meta-analysis of 65 studies (80,932 people with CKD) found a pooled prevalence of clinical depression of 26.5% (95% CI 23.1% to 30.1%), higher in people on hemodialysis than in those not yet on dialysis (29.9% vs. 18.5%) (Adejumo et al., Journal of Nephrology, 2024) [5].
What Is Chronic Kidney Disease?
Chronic kidney disease (CKD) is a condition where the kidneys are damaged over time and gradually lose their ability to work. The damage lasts for more than a few months.
Your kidneys do a lot of heavy lifting. They clean the blood by removing waste and extra fluid, which leaves the body as urine. They help control blood pressure and balance salt and minerals. They also help the body make red blood cells and keep bones strong.
How CKD develops: in a healthy kidney the nephron filters clean the blood; in CKD the filters are damaged and waste builds up.
CKD is far more common than most people realize. It is estimated that about one in seven American adults has it. Most of those people don't know it because the early stages usually have no symptoms.
What are the symptoms of chronic kidney disease?
Symptoms tend to develop slowly over time. Loss of kidney function can cause a buildup of fluid or waste in the body. It can also cause acids, potassium, and phosphate to build up in the blood.
Here's the catch: most people with kidney disease have no symptoms until the very last stages. This is called advanced kidney disease. When CKD becomes advanced, the loss of kidney function can cause:
Symptom | What It Feels Like |
Nausea and vomiting | Ongoing stomach upset |
Loss of appetite | Not wanting to eat |
Fatigue and weakness | Constant tiredness |
Sleep problems | Trouble sleeping |
Decreased mental sharpness | Foggy thinking |
High blood pressure that's hard to manage | BP stays high despite treatment |
Shortness of breath | Happens if fluid builds up in the lungs |
What are the five stages of chronic kidney disease?
To find out what stage you're in, your healthcare team performs a blood test called the estimated glomerular filtration rate (eGFR). This measures how much blood the kidneys filter each minute, recorded as milliliters per minute (mL/min). A low eGFR number means the kidneys are working less well.
As part of staging, your healthcare professional may also test for protein in your urine.
Kidney Disease Stage | eGFR (mL/min) | Kidney Function |
Stage 1 | 90 or above | Healthy kidney function |
Stage 2 | 60 to 89 | Mild loss of kidney function |
Stage 3a | 45 to 59 | Mild to moderate loss of kidney function |
Stage 3b | 30 to 44 | Moderate to severe loss of kidney function |
Stage 4 | 15 to 29 | Severe loss of kidney function |
Stage 5 | Less than 15 | Kidney failure (end-stage kidney disease) |
When the kidneys no longer work at the level needed to keep a person alive, it's called end-stage kidney disease. This happens when you have an eGFR under 15.
The 5 stages of kidney disease, measured by the eGFR blood test in mL/min, from healthy function to kidney failure.
When should you see a doctor about chronic kidney disease?
If you have an ongoing health condition that raises your risk of kidney disease, your healthcare professional may want to monitor your kidneys. Long-standing high blood pressure, diabetes, or an autoimmune disease such as lupus can all damage the kidneys.
Regular checkups to monitor kidney function may include blood tests and tests to check for protein in the urine. You may see your doctor every 6 to 12 months for these tests. If results show possible kidney problems, you may be referred to a nephrologist, a doctor who specializes in kidney diseases.
The earlier CKD is detected, the easier it is to treat. That's why regular checkups matter.
What causes chronic kidney disease?
CKD happens when a disease or condition hurts kidney function. Often, it has more than one cause.
Inside each kidney are filtering units called nephrons. Each nephron contains a filter called a glomerulus, made of tiny blood vessels called capillaries. Small molecules like water, minerals, nutrients, and waste pass through the capillary walls. Large molecules, such as proteins and red blood cells, stay in the blood. The filtered material then moves into the tubule, where the water, nutrients, and minerals the body needs return to the bloodstream. The extra water and waste become urine. When disease damages this system over months, kidney function declines.
Cause | How It Damages the Kidneys |
Type 1 or type 2 diabetes | Most common cause of kidney disease |
High blood pressure | Strains the kidney's filters |
Autoimmune diseases (lupus, sarcoidosis, Sjogren syndrome) | Immune system attacks kidney tissue |
Polycystic kidney disease or other inherited kidney diseases | Genetic conditions that impair structure |
Prolonged urinary tract obstruction | Conditions like enlarged prostate or urinary tract tumors block urine flow |
Vesicoureteral reflux | Urine backs up into the kidneys |
Certain medicines | Lithium, large doses of ibuprofen or other NSAIDs, immune-suppressing drugs |
What are the risk factors for chronic kidney disease?
Chronic kidney disease can become more likely because of a number of risk factors.
Risk Factor | Detail |
Diabetes | Type 1 and type 2 both increase risk |
High blood pressure | A major driver of kidney damage |
Heart disease | Raises overall risk |
Smoking | Can hurt the kidneys and make existing damage worse |
Being overweight | Adds strain on the body's systems |
Race and ethnicity | Being Black, Native American, or Asian American raises risk |
Family history of kidney disease | Genetics play a role |
Kidney shape or size problems | Structural changes or defects |
Older age | Risk increases as you get older |
Frequent use of kidney-damaging medicines | Especially certain pain relievers |
What complications can chronic kidney disease cause?
Chronic kidney disease (CKD) can affect almost every part of the body. Complications include:
Complication | What Happens |
High blood pressure | Kidneys can't remove extra salt and water, raising BP, which causes more kidney damage |
Acid buildup (acidosis) | Kidneys can't remove extra acids; can harm bone health and break down protein |
Fluid retention | Leg swelling, high blood pressure, or fluid in the lungs (pulmonary edema) causing shortness of breath |
High potassium (hyperkalemia) | May happen suddenly in later stages; can damage the heart and be life-threatening |
Anemia | Not enough healthy red blood cells to carry oxygen to tissues |
Heart disease | Arteries stiffen and clog, raising blood pressure |
Weak bones | Higher risk of bone fractures |
Sexual health concerns | Lower sex drive, erectile dysfunction, or reduced fertility |
Central nervous system damage | Trouble concentrating or personality changes, usually in very late stages |
Immune system changes | Lowered immune response, higher infection risk |
Pericarditis | Inflammation of the membrane covering the heart in advanced disease |
Pregnancy complications | Both mother and unborn baby may be at risk |
Lasting kidney damage | Dialysis or a kidney transplant may be needed to survive |
End-stage kidney disease is fatal unless a person gets a kidney transplant or starts dialysis, a treatment that does the job of the kidneys.
How is chronic kidney disease diagnosed?
To diagnose CKD, your healthcare professional starts by assessing your risk. They might ask about your symptoms, including any changes in your urinary habits. They may ask about your personal or family history of kidney disease, and about other conditions such as diabetes, high blood pressure, or autoimmune or inherited diseases. They'll also review any medicines you take.
A physical exam follows. The exam may check for problems with the heart or blood vessels. A neurological exam is also common. Tests help show how serious the kidney disease is. This is called staging the disease.
Diagnostic Test | What It Does |
Blood tests | Look for levels of waste products like creatinine and urea in the blood |
Urine tests | Check for protein (albumin) and blood in the urine; can reveal signs and clues to the cause |
Imaging tests (ultrasound) | Shows the structure and size of the kidneys |
Kidney biopsy | A long, thin needle removes a small kidney tissue sample through the skin, often guided by ultrasound; done when the cause isn't clear, especially if kidney function is quickly declining and there's a lot of protein in the urine |
How is chronic kidney disease treated?
Depending on the cause, some types of kidney disease can be treated. Often, though, chronic kidney disease has no cure. Even in that case, treatment is still needed to preserve kidney function for as long as possible. Treatment usually aims to help manage symptoms, reduce complications, and slow the progress of the disease. [2]
Treating the Cause
Your healthcare team will work with you on ways to slow down the progression and manage what's causing it. Treatment options vary by cause, for instance lowering high blood pressure or managing diabetes. But kidney damage can continue to worsen even after an underlying condition has been controlled.
Slowing the Progression
No matter what causes kidney disease, there are things you can do to protect the kidneys and slow down the rate of function loss:
Strategy | How It Helps |
Low-salt diet | Avoid adding extra salt; limit sodium to around 2,000 milligrams a day |
Blood pressure management | Regular home checks; aim for 130/80 or less; diet, exercise, and medicines help |
Lower protein diet | Reduces how hard kidneys need to work to get rid of extra waste; a dietitian helps plan it |
ACE inhibitors or ARBs | Blood pressure medicines shown to protect the kidneys |
SGLT2 inhibitors | Diabetes drugs that also protect the kidneys and heart; most helpful for mild to moderate disease, especially with protein in the urine |
Treating Complications
Complications can be managed to make you more comfortable:
Complication | Treatment Approach |
High blood pressure | Often more than one medicine; an ACE inhibitor or ARB plus a diuretic (water pill) that removes extra fluid; frequent blood tests may be needed at first |
Swelling (fluid retention) | Diuretics maintain fluid balance and reduce swelling |
Anemia | Erythropoietin shots help the body make red blood cells; iron pills or iron infusions may also be needed |
Heart disease risk | Statins lower cholesterol; a healthy diet and regular exercise also matter |
Bone disease | Calcium and vitamin D supplements; low phosphorus diet; phosphate binders taken with meals |
Acid buildup | Sodium bicarbonate (baking soda pills) if blood bicarbonate drops; eating less animal protein may help |
Your healthcare professional might recommend regular follow-up testing to check if the disease is getting worse. In many cases, starting treatment earlier can help prevent severe complications.
How are dialysis and transplant used for end-stage kidney disease?
Complete or near-complete kidney failure happens when the kidneys can't keep up with waste, fluid, and salt clearance on their own. Symptoms may worsen: poor appetite, lack of energy, poor sleep, mental decline, and daily nausea. Lab tests show very low kidney function and high potassium in the blood.
Treatment options for kidney failure are called kidney replacement therapy:
Option | How It Works |
Kidney transplant | Surgery places a healthy kidney from a deceased or living donor into your lower belly; blood vessels are attached and the new kidney's ureter connects to your bladder; your own kidneys are left in place; requires lifelong anti-rejection medicines; considered the best treatment but not everyone qualifies; you don't need to be on dialysis to have one |
Hemodialysis | A machine filters waste and extra fluid from your blood; usually done in a dialysis center for 3 to 4 hours, three times a week; some people qualify to do it at home |
Peritoneal dialysis | A thin tube is placed into the stomach area; dialysis solution fills that space, absorbs waste and fluid, and is drained after a few hours; done at home, often overnight with a cycler machine while you sleep |
Comprehensive medical management | For those who choose not to have dialysis or a transplant; care focuses on treating symptoms and keeping you comfortable as the disease progresses to end of life, with a palliative care team |
Treatment at every stage: slow the damage (low-salt and lower-protein diet, blood pressure target 130/80, ACE/ARB and SGLT2 medicines), manage complications, and choose among end-stage options.
Which lifestyle and home remedies help with chronic kidney disease?
As part of chronic kidney disease treatment, your healthcare team might suggest a special diet. Careful choices about what to eat and drink can limit how hard the kidneys have to work. Ask for a referral to a registered dietitian. Your diet may need to change based on how well your kidneys are working and your overall health:
Dietary Change | Details |
Avoid added salt | Skip salty snacks, frozen dinners, canned soups and vegetables, processed meats, and cheeses |
Choose lower potassium foods | High-potassium foods include bananas, oranges, potatoes, spinach, and tomatoes. Low-potassium options include apples, cabbage, carrots, green beans, grapes, and strawberries. Stop salt substitutes (many contain potassium) if you have kidney failure |
Limit protein | Your dietitian estimates daily grams; high-protein foods include lean meats, eggs, milk, cheese, and beans; lower-protein options include vegetables, fruits, breads, and cereals |
How can people cope with chronic kidney disease?
Receiving a chronic kidney disease (CKD) diagnosis can be worrying, and dietary changes can feel confusing. If you feel overwhelmed:
Connect with others who have kidney disease. Ask your healthcare professional about support groups, or contact the American Association of Kidney Patients, the National Kidney Foundation, or the American Kidney Fund.
Stick to your usual routine as much as possible. Continue activities you enjoy.
Be active most days. Aim for at least 30 minutes of physical activity most days of the week, if your doctor says it's OK. This can help with fatigue and stress.
Talk with someone you trust. A friend, family member, faith leader, or a referred social worker or counselor.
How should you prepare for an appointment about chronic kidney disease?
You may start by seeing your primary care professional. If lab tests show kidney damage, you might be referred to a nephrologist.
Before your appointment:
Be aware of any restrictions before the appointment (such as diet changes before tests).
Write down any symptoms you have, including ones that may seem unrelated, and when they started.
Write down key personal information, including major stresses or recent life changes.
Make a list of all medicines, vitamins, or supplements you take and the amounts.
Consider bringing a family member or friend along.
Write down questions to ask.
Questions to ask your healthcare team:
Topic | Questions |
Kidney function | What's the level of damage to my kidneys? Is my kidney function getting worse? Can the damage be undone? |
Tests | What kinds of tests do I need? How often do I need tests to check kidney function? |
Cause and treatment | What's causing my condition? What next steps do you recommend? Are there alternatives? What are the side effects? |
Diet | Do I need to eat a special diet? Can you refer me to a dietitian? |
Other conditions | How can I best treat my other health conditions together? |
Your doctor may ask:
When did you first start having symptoms?
How have your symptoms changed over time?
Have you been diagnosed with or treated for high blood pressure?
Have you noticed changes in your urinary habits?
How can you prevent chronic kidney disease?
Certain everyday steps can lower the risk of developing chronic kidney disease.
Prevention Step | Why It Matters |
Follow OTC medicine instructions | Taking too many pain relievers like ibuprofen for too long could lead to kidney damage |
Keep a healthy weight | Stay physically active most days; talk to your healthcare team about a weight-loss plan |
Don't smoke | Smoking hurts the kidneys and makes existing damage worse |
Manage medical conditions | Follow a low-sodium diet, check blood pressure at home, and take prescribed medicines |
Conclusion
Chronic kidney disease damages the kidneys gradually, and it affects about one in seven American adults, most of whom don't know it. Early stages rarely cause symptoms, which is why routine blood and urine tests are so important for people at risk.
The five stages, measured by eGFR, show just how much the kidneys have declined. Diabetes and high blood pressure are the most common drivers. While there is no cure, treatment can slow the damage through blood pressure control, a low-salt diet, certain protective medicines, and managing complications like anemia and bone disease. When the kidneys fail, dialysis or a kidney transplant becomes necessary to survive.
Ready to take the next step? If you have diabetes, high blood pressure, or a family history of kidney disease, ask your doctor about kidney function testing at your next checkup. Bring your symptoms, your medicine list, and your questions to make the most of your visit.
Frequently Asked Questions
What is chronic kidney disease?
Chronic kidney disease (CKD) is a condition in which the kidneys are damaged over more than a few months and gradually lose their ability to filter blood, remove waste, and balance fluids and minerals.
How common is chronic kidney disease?
It is estimated that chronic kidney disease affects about one in seven American adults, and most of those people don't know they have it because early stages have no symptoms.
What causes chronic kidney disease?
The most common causes are type 1 and type 2 diabetes and high blood pressure. Other causes include autoimmune diseases like lupus, polycystic kidney disease, prolonged urinary tract obstruction, vesicoureteral reflux, and certain medicines such as lithium or large doses of NSAIDs.
What are the symptoms of chronic kidney disease?
Early stages usually have no symptoms. In advanced disease, symptoms may include nausea, vomiting, loss of appetite, fatigue, sleep problems, decreased mental sharpness, hard-to-manage high blood pressure, and shortness of breath from fluid in the lungs.
What are the stages of kidney disease?
Kidney disease is staged 1 through 5 based on the eGFR blood test, which measures how many milliliters of blood the kidneys filter per minute. Stage 1 is 90 or above; Stage 2 is 60 to 89; Stage 3 is 30 to 59; Stage 4 is 15 to 29; and Stage 5 (under 15) is kidney failure.
Is chronic kidney disease curable?
Often, chronic kidney disease has no cure. Treatment focuses on managing symptoms, reducing complications, and slowing the progression of the disease for as long as possible.
What is eGFR?
The estimated glomerular filtration rate (eGFR) is a blood test that measures how much blood the kidneys filter each minute, in milliliters per minute (mL/min). A low eGFR number means the kidneys are working less well.
Can you slow down chronic kidney disease?
Yes. Slowing progression includes a low-salt diet (around 2,000 mg sodium a day), keeping blood pressure at 130/80 or less, a lower protein diet, ACE inhibitor or ARB medicines, and SGLT2 inhibitor drugs for people with diabetes.
What is end-stage kidney disease?
End-stage kidney disease happens when the eGFR falls below 15 and the kidneys no longer work well enough to keep a person alive. Without dialysis or a kidney transplant, it is fatal.
What is the difference between hemodialysis and peritoneal dialysis?
Hemodialysis uses a machine to filter blood, usually at a dialysis center for 3 to 4 hours three times a week. Peritoneal dialysis uses the stomach lining as a filter: dialysis solution fills the stomach area, absorbs waste, and is drained after a few hours, usually at home overnight.
Is a kidney transplant the best treatment for kidney failure?
A kidney transplant is considered the best treatment for kidney failure. However, not everyone qualifies, and it requires a detailed evaluation and lifelong anti-rejection medicines. You don't need to be on dialysis to have a transplant.
External Resources
For authoritative information, see:
References
Mayo Clinic Staff. Chronic kidney disease - Symptoms and causes. Mayo Clinic. December 9, 2025. https://www.mayoclinic.org/diseases-conditions/chronic-kidney-disease/symptoms-causes/syc-20354521
Mayo Clinic Staff. Chronic kidney disease - Diagnosis and treatment. Mayo Clinic. December 9, 2025. https://www.mayoclinic.org/diseases-conditions/chronic-kidney-disease/diagnosis-treatment/drc-20354527
Hill NR, Fatoba ST, Oke JL, et al. Global prevalence of chronic kidney disease - a systematic review and meta-analysis. PLoS One. 2016;11(7):e0158765. PMID 27383068. https://doi.org/10.1371/journal.pone.0158765
Nuffield Department of Population Health Renal Studies Group; SGLT2 Inhibitor Meta-Analysis Cardio-Renal Trialists' Consortium. Impact of diabetes on the effects of sodium glucose co-transporter-2 inhibitors on kidney outcomes: collaborative meta-analysis of large placebo-controlled trials. Lancet. 2022;400(10365):1788-1801. PMID 36351458. https://doi.org/10.1016/S0140-6736(22)02074-8
Adejumo OA, Edeki IR, Sunday Oyedepo D, et al. Global prevalence of depression in chronic kidney disease: a systematic review and meta-analysis. Journal of Nephrology. 2024;37(9):2455-2472. PMID 38954184. https://doi.org/10.1007/s40620-024-01998-5
Medical disclaimer
This article is for general educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the guidance of your healthcare professional with any questions about your health. In a medical emergency, call 911 or your local emergency number.
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