Chronic Kidney Disease: Symptoms, 5 Stages and Treatment
Medically Reviewed by Dr. Andrew Stein MD, Consultant Nephrologist (Hospital Kidney Specialist). Last updated: June 2026
Chronic Kidney Disease (CKD) is a long-term condition where the kidneys do not function as efficiently as they should, or have a structural problem (with normal kidney function).
It is not a single diagnosis but a syndrome with many different underlying causes (and hence different treatments).
The term ‘chronic’ may sound alarming. However, it simply means the condition has been present for at least three months.
CKD is usually silent in early stages, meaning many people are unaware they have it unless tested.
Key Facts and Statistics
- Prevalence: CKD affects approximately 10% of the population (1 in 10 adults).
- Prognosis: Most cases are in older people (and age-related) and remain stable or progress slowly.
- Progression Risk: Fortunately only ~1% progress to kidney failure; but risk is higher in people with diabetes, significant proteinuria, or low eGFR.
- Primary Risk: Cardiovascular disease is the leading concern for CKD patients.
How is CKD Defined?
Doctors use two main criteria to diagnose CKD (present for ≥3 months):
Functional CKD
Structural CKD
Evidence of kidney damage, even if eGFR is normal:
- Albuminuria/proteinuria
- Haematuria
- Structural abnormalities (e.g. polycystic kidneys)
- Biopsy-proven disease
5 CKD Stages (based on eGFR and Albuminuria)
CKD is classified using both kidney function (eGFR) and urine protein levels (ACR).
eGFR Stages
| Stage |
eGFR |
Description |
| 1–2 |
≥60 |
Normal or near-normal function with evidence of damage |
| 3A |
45–59 |
Mildly decreased function |
| 3B |
30–44 |
Mild–moderate reduction |
| 4 |
15–29 |
Severely reduced function |
| 5 |
<15 |
Kidney failure |
A normal GFR in young adults is ~90–120 mL/min. Kidney function gradually declines with age, though this varies between individuals. So a GFR of 50 ml/min can be normal in an 80 year old and they do not have CKD.
Albuminuria (ACR) Categories
| Category |
ACR Level |
Description |
| A1 |
<3 mg/mmol |
Normal or mildly increased |
| A2 |
3–30 mg/mmol |
Moderately increased |
| A3 |
>30 mg/mmol |
Severely increased |
The urinary ACR levels (‘A1-3′) are combined with the CKD stage (Grade or ‘G 1-5’) to estimate the outlook for someone with CKD; i.e. likelihood of eventually needing dialysis or a kidney transplant – with a higher G and/or higher A, indicating a worse outlook.
In other words, CKD can be described in one patient as ‘CKD G4 A3’, and this has a worse outlook than for a patient with ‘CKD G2 A1’. So a higher level of albuminuria worsens the outlook as does a lower GFR.
👉 Why this matters
Higher albuminuria significantly increases the risk of cardiovascular disease as well as CKD progression—even if eGFR is not that low.
CKD vs Acute Kidney Injury (AKI)
- CKD: Long-term, present ≥3 months; usually not reversible – but can be slowed down
- AKI: Rapid decline in kidney function over hours to days, often reversible
This distinction is important, as AKI may require urgent treatment.
Causes of CKD
The most common causes include:
- Unknown cause (30%) – Often with small scarred kidneys
- Diabetes mellitus (20%) – Leading global cause
- Hypertension – Causes vascular and glomerular damage
- Glomerulonephritis (GN) – Immune-mediated damage
- Obstructive nephropathy – Blocked urine flow (e.g. prostate, stones)
- Renovascular disease (RVD) – Narrowed kidney arteries
- Genetic disorders – e.g. ADPKD (adult polycystic kidney disease)
- Tubulo-interstitial nephritis (TIN) – Often medication-related
Symptoms of CKD
CKD is often asymptomatic until advanced stages.
When symptoms occur, they may include:
- Fatigue
- Swelling (oedema)
- Shortness of breath
- Itching or muscle cramps
- Nausea or poor appetite
- Nocturia (night-time urination)
These symptoms typically appear when eGFR falls below 30 (Stage 4).
Red Flag Symptoms (Seek Urgent Medical Attention)
- Chest pain or severe breathlessness
- Very low urine output
- Severe swelling
- Palpitations (possible high potassium)
- Severe weakness (possible high potassium)
Treatment (General) & Lifestyle Management
Most patients benefit from “kidney-protective” treatments:
- ACE inhibitors / ARBs – Reduce proteinuria and protect kidneys
- SGLT2 inhibitors – Slow progression and improve heart outcomes
- Statins – Reduce cardiovascular risk
4 Key Lifestyle Measures
- Blood pressure control: Target ~130/80 mmHg
- Avoid NSAIDs: Use paracetamol instead
- Stop smoking
- Stay active
Diet and Fluid Advice
- Maintain a balanced diet
- Avoid very high-protein diets in advanced CKD
- Potassium and phosphate restriction may be needed in later stages (under specialist guidance)
👉 Fluid intake: Stay well hydrated, but follow medical advice—fluid intake may need adjustment in advanced CKD or heart conditions. In fact, some patients will need fluid restiction.
Treatment (Specific, by Cause)
- GN → Immunosuppression
- Obstruction → Relieve blockage
- TIN → Stop offending drug +/- steroids
- RVD → Cardiovascular risk management; ACE/ARBs/SGLT2is may need to be stopped
- Diabetic nephropathy → Tight glucose control
Other Issues
Medication Safety (Drugs to Avoid)
- Many drugs require dose adjustment (reduction) in CKD
- Avoid NSAIDs (e.g. ibuprofen, naproxen)
- Inform all doctors and nurses you have CKD
- Caution with contrast dye (used CT scans etc)
Vaccinations
CKD increases infection risk. Recommended vaccines include:
- Annual flu vaccine
- Pneumococcal vaccine
- COVID boosters (as advised)
Complications
- Cardiovascular disease (leading cause of death)
- Anaemia
- Mineral and bone disorder (CKD-MBD)
- Metabolic acidosis (too much acid in the blood)
- Hyperkalaemia (too much potassium in the blood)
Prognosis
- Very variable
- Most people with Stages 1–3 remain stable long-term.
- Only a small proportion progress to kidney failure, but risk depends on:
- eGFR level
- Albuminuria
- Underlying cause
Cardiovascular health is the main determinant of outcomes.
When to See a Kidney Specialist (Nephrologist)
Referral is usually recommended if:
- eGFR <30 (Stage 4–5)
- Rapid decline in kidney function
- Significant proteinuria (A3)
- Unclear cause
- Family history of CKD or ESRF (e.g. Polycystic Kidneys or Alport Syndrome)
- Difficult-to-control blood pressure
CKD requires regular monitoring to track progression:
- Blood tests (eGFR, creatinine)
- Urine ACR
- Blood pressure checks
Frequency depends on stage:
- Early CKD: yearly
- More advanced CKD: every 3–6 months (or more frequently)
Who Should Be Tested for CKD? (Screening)
CKD screening is recommended in people with:
- Diabetes
- High blood pressure
- Cardiovascular disease
- Family history of kidney disease
- Older age
Testing includes a blood test (eGFR) and urine test (ACR).
Frequently Asked Questions
Can CKD be reversed?
Usually not, but progression can often be slowed or stabilised.
Why are urine tests important?
They detect albumin, an early marker of kidney damage and risk.
Can I take painkillers?
Avoid NSAIDs; paracetamol is generally safer.
Do I need a special diet?
Early CKD: general healthy diet
Later CKD: possible potassium/phosphate restriction
Is exercise safe?
Yes—moderate activity is strongly recommended.
Final Thought
CKD is common, often silent, and usually manageable. Early detection, regular monitoring, and good cardiovascular care make a significant difference to long-term outcomes.
