Chronic Kidney Disease (CKD):
Stages, Symptoms & Modern Treatment

At a glance

FrequencyBy estimates, affects roughly one in ten adults in Germany - many do not know they have it (rates are broadly similar in other Western countries)
DefinitionKidney damage or reduced kidney function (eGFR < 60) over at least three months
Most common causesDiabetes and high blood pressure - together responsible for a large share of cases
Key valueseGFR (estimated glomerular filtration rate) and UACR (urine albumin-to-creatinine ratio)
TreatmentBlood pressure control, ACE inhibitors/ARBs, SGLT2 inhibitors, finerenone if needed - lifestyle, avoiding nephrotoxic medications
ICD-10N18 (chronic kidney disease)

Table of contents

  1. What is CKD?
  2. Stages
  3. Symptoms
  4. Causes and risk factors
  5. Diagnosis
  6. Treatment: kidney protection
  7. Diet
  8. Dialysis and transplantation
  9. Everyday life with CKD
  10. How brite helps you
  11. FAQ
  12. Related topics

1. What is CKD?

Chronic kidney disease (CKD) means that the kidneys are reduced in function over a longer period (at least three months), or that there is structural kidney damage. The kidneys normally filter waste products and excess water out of the blood and regulate blood pressure, the mineral balance, and blood formation.1

By estimates, CKD affects roughly one in ten adults in Germany - and rates are broadly similar across other Western countries. Most people are unaware of it for a long time, because in early stages the disease usually causes no symptoms. As kidney damage progresses, the risk of cardiovascular disease and overall mortality rises markedly.1,2

The good news: treatment has fundamentally improved In recent years, new medications have become available - above all SGLT2 inhibitors and finerenone - that can demonstrably slow the course of CKD. The prerequisite: the disease is recognized early and treated consistently.

2. Stages

CKD is classified according to the KDIGO classification using two parameters: the eGFR (estimated kidney function) and albuminuria (protein in the urine).1

GFR stages

G1 eGFR ≥ 90
Normal or increased kidney function, but signs of kidney damage (e.g. albuminuria)
G2 eGFR 60-89
Mildly reduced with signs of kidney damage
G3a eGFR 45-59
Mildly to moderately reduced
G3b eGFR 30-44
Moderately to severely reduced
G4 eGFR 15-29
Severely reduced
G5 eGFR < 15
Kidney failure - dialysis or transplantation usually necessary

Albuminuria categories

  • A1: normal to mildly increased
  • A2: moderately increased - an important early indicator of kidney damage and cardiovascular risk
  • A3: severely increased

The higher the stage and the stronger the albuminuria, the higher the risk of the disease progressing and of cardiovascular complications.1

3. Symptoms

Early stages: hardly any symptoms CKD usually causes no symptoms in early stages - which is why it is often only discovered late. Symptoms mostly only appear in advanced stages.
  • Fatigue and reduced performance
  • Fluid retention (edema) - especially in the legs, feet, and face
  • Shortness of breath
  • Nausea, loss of appetite
  • Itching
  • Difficulty concentrating
  • Changed urine amount (more or less than normal), foaming urine
  • High blood pressure - often both a cause and a consequence of CKD
  • Anemia - the kidneys produce less erythropoietin

4. Causes and risk factors

  • Diabetes: the most common cause of CKD. Type 2 diabetes and type 1 diabetes can damage the small blood vessels of the kidneys (diabetic nephropathy).
  • High blood pressure: the second most common cause. Long-term raised blood pressure damages the kidney vessels. At the same time, CKD can raise blood pressure further - a vicious circle.
  • Glomerulonephritis: inflammatory kidney diseases of various causes.
  • Polycystic kidney disease (ADPKD): a hereditary disease with cyst formation in the kidneys. The most common hereditary kidney disease.
  • Urinary tract diseases: recurring urinary tract infections, urinary outflow obstruction, kidney stones.
  • Medications: long-term use of NSAIDs (ibuprofen, diclofenac), certain antibiotics, contrast agents. More: drug interactions.
  • Other risk factors: age, obesity, smoking, family history, heart failure.

5. Diagnosis

Diagnosing CKD is usually straightforward - if you think of it.1

  • eGFR (estimated GFR): calculated from the creatinine in the blood. The most important value for assessing kidney function. In certain situations, cystatin C can also be measured for a more accurate estimate.
  • UACR (urine albumin-to-creatinine ratio): a simple urine test that detects increased protein excretion. The KDIGO 2024 guideline emphasizes the importance of the UACR especially in screening and risk assessment.1
  • Urine sediment and dipstick: signs of blood, protein, or inflammation in the urine.
  • Blood pressure: measure regularly.
  • Kidney ultrasound: size, shape, signs of obstruction, cysts, stones.
  • Blood values: potassium, phosphate, calcium, urea, complete blood count (anemia?), HbA1c (diabetes?).
Screening in people at risk - KDIGO 2024 The KDIGO 2024 guideline recommends regular CKD screening with eGFR and UACR in people with diabetes, high blood pressure, or other risk factors. Early stages of CKD are often still very treatable - the later the diagnosis, the worse the prognosis.

More: preparing for a doctor's appointment, understanding blood test results.

6. Treatment: kidney protection

The goal of treatment is to slow the progression of CKD, prevent complications, and lower cardiovascular risk. The KDIGO 2024 guideline defines a multi-pillar kidney-protective strategy.1

Pillar 1 Blood pressure control & RAS inhibitors

The systolic target is usually below 120 mmHg per KDIGO 2024. RAS inhibitors (ACE inhibitors or ARBs) are usually the agents of choice for CKD with albuminuria - they not only lower blood pressure but also act directly to protect the kidneys.1

Pillar 2 SGLT2 inhibitors - the new pillar
Dapagliflozin, empagliflozin, and others
Can lower the progression of kidney damage and cardiovascular risk - independently of whether diabetes is present. Recommended by KDIGO 2024 with a strong recommendation.1
Pillar 3 Further modern options
Finerenone (non-steroidal MRA)
A new mineralocorticoid receptor antagonist that can reduce the progression of kidney damage and cardiovascular events in CKD with diabetes. Recommended in KDIGO 2024.1
GLP-1 receptor agonists (e.g. semaglutide)
Can reduce cardiovascular and renal events in people with CKD who have diabetes and/or obesity. Listed as a new treatment option in KDIGO 2024.
Alongside Diabetes, lifestyle & medication review
  • Diabetes control: with diabetic nephropathy, good blood sugar control (an individual HbA1c target) is crucial.
  • Lifestyle: stopping smoking, weight control, regular exercise, reducing salt.
  • Medication review: dose adjustment with reduced kidney function, observing sick-day rules (pausing certain medications during an acute illness). More: discontinuing medication.
Caution: avoid NSAIDs with CKD NSAIDs (ibuprofen, diclofenac, and the like) can worsen kidney function and should usually be avoided with CKD - especially in higher stages. Contrast agents and certain antibiotics can also strain the kidneys. With pain, agree with your treating practice on which alternatives are suitable.

7. Diet

  • Reduce salt: can improve blood pressure and edema.
  • Protein: KDIGO 2024 recommends a moderate protein intake for most people with CKD - no strict restriction, but no excess either.
  • Potassium: in advanced stages, a potassium-adjusted diet may be necessary - plant-based potassium is less bioavailable than potassium from highly processed foods.
  • Phosphate: avoid foods with added phosphate (ready meals, cola, processed cheese).
  • Dietary counseling: professional dietary counseling is usually recommended - especially in advanced stages.

8. Dialysis and transplantation

When kidney function drops so far that the body can no longer adequately excrete waste products and water, kidney replacement therapy becomes necessary - usually from stage G5.1

Hemodialysis
The blood is cleaned outside the body via a machine. Usually three times a week for several hours at a dialysis center. Home hemodialysis is an option for some people.
Peritoneal dialysis
The peritoneum serves as a filter. Can usually be done at home - offers more flexibility in everyday life.
Kidney transplantation
The best long-term treatment for most people with kidney failure. Can come from a living donor or from deceased organ donors. The waiting time for a donor organ can be several years.
Get informed early - from G4 onwards According to the guideline, education about kidney replacement procedures should happen early - usually from stage G4 onwards - so that preparations can be made in good time (dialysis access, transplant workup).1

9. Everyday life with CKD

  • Medications: regular and punctual intake. Note dose adjustment with reduced kidney function. No NSAIDs without checking first. More: taking medication correctly.
  • Check-ups: regular blood and urine checks (eGFR, UACR, potassium, complete blood count). The intervals depend on the stage.
  • Blood pressure: measure regularly - ideally at home. Discuss target values with your practice.
  • Vaccinations: the flu vaccination and the pneumococcal vaccination are usually recommended. With advanced CKD, special vaccination recommendations apply.

How brite helps you with CKD

Ramipril in the morning, dapagliflozin with it, finerenone in the evening, furosemide as needed, plus the phosphate binder with meals - and check eGFR and potassium every three months. CKD treatment is multitasking. brite brings structure to it.

  • Intake reminders - take ACE inhibitors, SGLT2 inhibitors, finerenone, and blood pressure medications on time - and phosphate binders with meals. brite reminds you reliably, including the time-critical medications. Set up a reminder
  • Interaction check - NSAIDs with CKD? Potassium-sparing diuretics plus an ACE inhibitor? Preparing for contrast agents? brite warns you about risky combinations that are particularly relevant for the kidneys. Check now
  • Health journal - document eGFR, UACR, blood pressure, potassium, and weight over time. That way you see early if the course is worsening - and can counteract it. Track your progress
  • Digital medication plan - all your medications clearly laid out for nephrology, cardiology, diabetology, and your GP - especially important because many specialists are involved with CKD. Go to the medication plan
Get started for free now
brite app

FAQ: common questions about chronic kidney disease

The eGFR (estimated glomerular filtration rate) is the most important lab value for assessing kidney function. It is calculated from the creatinine in the blood and indicates how well the kidneys filter the blood. A value below 60 over at least three months points to reduced kidney function.1
In early stages the progression can usually be slowed or stopped - through blood pressure control, SGLT2 inhibitors, and treatment of the underlying condition. Kidney function that has already been lost, however, mostly cannot be restored. That is why early detection is so important.
Medications (e.g. dapagliflozin, empagliflozin) that were originally developed for diabetes but can also protect the kidneys and the heart independently of diabetes. According to KDIGO 2024, they are among the most important new pillars of CKD treatment.1
Not necessarily. In many people the progression of CKD can be slowed so far with modern treatment that dialysis is not needed, or only much later. When kidney function drops very sharply, however (stage G5), kidney replacement therapy usually becomes necessary.
With CKD, NSAIDs (ibuprofen, diclofenac) should usually be avoided, as they can worsen kidney function. Alternatives (e.g. acetaminophen) should be discussed with your treating practice.
Through simple lab tests: eGFR (a blood test) and UACR (a urine test). The KDIGO guideline recommends regular screening in people at risk (diabetes, high blood pressure, family history, age). Early CKD stages are usually symptom-free - only tests can detect them.1
A new non-steroidal mineralocorticoid receptor antagonist that can reduce the progression of kidney damage and cardiovascular events in CKD with diabetes. It is recommended as a new treatment option in KDIGO 2024.1
In early stages usually yes - with a focus on reducing salt and a balanced diet. In advanced stages, a diet adjusted for potassium, phosphate, and possibly protein may be necessary. Professional dietary counseling is recommended.
Type 2 diabetes High blood pressure Heart failure Ibuprofen Understanding blood test results Drug interactions

Sources

  1. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD. kdigo.org
  2. DEGAM S3 Guideline CKD in Primary Care (AWMF reg. no. 053-048, Update 2024), Germany. degam.de
  3. gesundheitsinformation.de (IQWiG): Chronic Kidney Disease. gesundheitsinformation.de
  4. German Society of Nephrology (DGfN). dgfn.eu
Medical disclaimer: This article is for general information and does not replace medical advice, diagnosis, or treatment. With reduced kidney function, medications should usually be taken, dosed, or stopped only in consultation with your treating practice. NSAIDs should usually be avoided with CKD. Treatment planning is always determined individually by nephrology or your GP practice. Last updated: April 2026.