CKD Stages 9 min read·Updated 22 July 2026 Clinician-reviewed

Stage 3 Kidney Disease (CKD)

A UK Consultant Nephrologist's plain-English guide to stage 3 chronic kidney disease — what an eGFR of 30–59 actually means, what you and your GP should be doing, and what slows it down.

  • Clinically Reviewed
  • NHS & NICE Aligned
  • UK Evidence-Based
  • Last Reviewed 22 July 2026

Professor Mohammed Mahdi Althaf

Consultant Nephrologist & Acute Physician

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Professor Mohammed Mahdi Althaf

MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN

Consultant Nephrologist & Acute Physician · GMC 7216325

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Direct answer

Stage 3 CKD = eGFR 30–59. Most people have no symptoms and are managed in primary care. The big wins are blood pressure control, an ACE-i/ARB if your urine ACR is up, an SGLT2 inhibitor where indicated, a low-salt diet and avoiding NSAIDs.

Key recommendation: Stage 3a = eGFR 45–59; stage 3b = eGFR 30–44.

Quick answer

✓ Best choices

  • Lower-potassium fruit: apples, pears, berries, grapes, pineapple
  • Vegetables prepared with the leaching method when potassium is a concern
  • Whole grains: oats, basmati rice, pasta, couscous, sourdough
  • Lean protein in measured portions: fish, chicken, eggs, tofu

✓ Foods to limit

  • Added salt and high-sodium processed foods
  • Phosphate additives (E338, E339, E340, E450, E451, E452) in processed meats, fizzy drinks, instant foods
  • Very high-potassium foods if your blood potassium is rising
  • Sugary drinks, energy drinks and ultra-processed snacks

Key takeaway

Stage 3 CKD = eGFR 30–59. Most people have no symptoms and are managed in primary care. The big wins are blood pressure control, an ACE-i/ARB if your urine ACR is up, an SGLT2 inhibitor where indicated, a low-salt diet and avoiding NSAIDs.

Who should be cautious

People on dialysis, post-transplant, pregnant or breastfeeding, or taking prescription medication — confirm with your renal team before changes.

Stage 3 Kidney Disease (CKD)

What stage 3 CKD means

Staging (KDIGO / NICE Ng203)

  • Stage 1: eGFR ≥ 90 with kidney damage (e.g. raised ACR)
  • Stage 2: eGFR 60–89 with kidney damage
  • Stage 3a: eGFR 45–59
  • Stage 3b: eGFR 30–44
  • Stage 4: eGFR 15–29
  • Stage 5: eGFR < 15 or on dialysis

CKD is also classified by urine albumin-to-creatinine ratio (ACR):

  • A1: < 3 mg/mmol (normal/mild)
  • A2: 3–30 mg/mmol (moderate)
  • A3: > 30 mg/mmol (severe)

A person with eGFR 50 and ACR 40 has stage 3a A3 — higher risk than 3a A1 despite the same eGFR.

Common Causes

  • Diabetes (commonest)
  • High blood pressure
  • Glomerular disease (e.g. IgA nephropathy)
  • Polycystic kidney disease
  • Recurrent infection or obstruction

Monitoring, diet and lifestyle

Monitoring (NICE Ng203)

  • eGFR and urine ACR at least once a year
  • More often (3–6 monthly) if eGFR falling, ACR > 30, or BP uncontrolled
  • Check potassium, bicarbonate, calcium, phosphate, PTH, haemoglobin when indicated
  • BP at every contact; home BP monitoring encouraged

DIET (UK renal dietitian guidance):

  • Salt < 6 g/day; read labels for sodium
  • Protein around 0.8 g/kg/day for most adults
  • Plenty of veg and fruit — potassium restriction is rarely needed at stage 3 unless blood potassium is high
  • Limit ultra-processed food (additive phosphate)
  • 1.5–2 L fluid/day unless told otherwise
  • Mediterranean or DASH pattern is well evidenced

Lifestyle

  • Stop smoking
  • Keep BMI in healthy range
  • Avoid NSAIDs (ibuprofen, naproxen, diclofenac) unless your kidney team agrees
  • Be cautious with herbal remedies and high-dose supplements
  • Alcohol within UK low-risk limits (≤ 14 units/week)

Treatment that slows progression

Blood Pressure

  • Target < 130/80 for most adults with CKD and raised ACR
  • Home monitoring helps avoid white-coat readings

ACE INHIBITOR or ARB:

  • First-line if ACR > 3 mg/mmol or you have diabetes with CKD
  • Examples: ramipril, lisinopril, losartan, candesartan
  • Recheck eGFR and potassium 1–2 weeks after starting or up-titrating

SGLT2 INHIBITOR (dapagliflozin or empagliflozin):

  • NICE-recommended for CKD with ACR ≥ 22.6 mg/mmol, with or without diabetes
  • Slows eGFR decline, reduces cardiovascular and kidney events

Diabetes & Cholesterol

  • HbA1c target individualised
  • Statin (usually atorvastatin 20 mg) for primary prevention in CKD

When To Refer To Nephrology

  • eGFR < 30
  • ACR > 70 mg/mmol
  • Rapid decline (> 25% and stage change within 12 months, or > 15 mL/min/year)
  • Uncontrolled BP on 4 drugs
  • Suspected genetic kidney disease or rare cause
Vitamins for CKD Stage 3
Related reading: Vitamins for CKD Stage 3.

Key practical tips

Designed for quick scanning — what to order, what to avoid, sensible portions, common mistakes.

  • Build a kidney plate: ½ vegetables and salad, ¼ whole-grain carb, ¼ protein
  • Cook from scratch when you can — it's the easiest way to control hidden salt and phosphate
  • Read labels for sodium ≤ 0.3 g per 100 g (low) and any 'E3-/E4-' phosphate additives
  • Discuss potassium and phosphate targets with your renal dietitian — they vary by stage

Clinical guidance

TL;DR summary

Stage 3 CKD = eGFR 30–59. Most people have no symptoms and are managed in primary care. The big wins are blood pressure control, an ACE-i/ARB if your urine ACR is up, an SGLT2 inhibitor where indicated, a low-salt diet and avoiding NSAIDs.

Key takeaways
  • Stage 3a = eGFR 45–59; stage 3b = eGFR 30–44.
  • Usually symptomless; found on routine bloods.
  • Yearly eGFR + urine ACR is the NICE minimum.
  • BP target < 130/80; ACE-i/ARB if ACR raised.
  • SGLT2 inhibitor slows progression in many.
Kidney Diet & Nutrition Considerations

At every stage of chronic kidney disease, what you eat shapes how the kidneys cope day-to-day. UK renal guidance (NICE NG203, KDIGO 2024, KDOQI 2020 nutrition) focuses on four levers: sodium (salt), potassium and phosphate awareness, sensible protein intake, and an overall whole-food, Mediterranean-style pattern. Targets are individual — your renal team uses your bloods (eGFR, potassium, phosphate, bicarbonate) to personalise them. Aim for a balanced plate built around vegetables, lower-potassium fruit, whole grains, modest portions of fish or lean protein, and unsaturated fats such as olive oil.

Foods to prioritise

  • Lower-potassium fruit: apples, pears, berries, grapes, pineapple
  • Vegetables prepared with the leaching method when potassium is a concern
  • Whole grains: oats, basmati rice, pasta, couscous, sourdough
  • Lean protein in measured portions: fish, chicken, eggs, tofu
  • Extra virgin olive oil as the main cooking fat (PREDIMED-style pattern)

Foods to limit

  • Added salt and high-sodium processed foods
  • Phosphate additives (E338, E339, E340, E450, E451, E452) in processed meats, fizzy drinks, instant foods
  • Very high-potassium foods if your blood potassium is rising
  • Sugary drinks, energy drinks and ultra-processed snacks

Potassium, phosphate and protein needs vary between individuals — please confirm personal targets with your renal team or dietitian. Browse the Kidney Diet Hub for more guides in this cluster.

Frequently asked questions

What is stage 3 kidney disease?

Stage 3 chronic kidney disease (CKD) means your kidneys are working at 30–59% of normal, measured by estimated glomerular filtration rate (eGFR 30–59 mL/min/1.73m²). It is split into 3a (eGFR 45–59) and 3b (eGFR 30–44). Around 5% of UK adults have stage 3 CKD; most are managed successfully by their GP with NICE-recommended monitoring.

What are the symptoms of stage 3 CKD?

Most people have no symptoms at stage 3 — it is usually picked up on a routine blood test. Possible signs include tiredness, ankle swelling, more frequent urination at night, mild blood pressure rise and itchy skin. New symptoms warrant a GP review and bloods.

What diet helps in stage 3 CKD?

UK renal dietitian guidance for stage 3 emphasises: less salt (under 6 g/day), moderate protein (0.8 g/kg/day for most adults), plenty of vegetables and fruit (potassium restriction is rarely needed at stage 3 unless blood potassium is high), limited ultra-processed food (additive phosphate), and adequate hydration. A Mediterranean-style or DASH diet is well evidenced.

How is stage 3 CKD monitored?

NICE NG203 recommends at least yearly eGFR and urine albumin-to-creatinine ratio (ACR) — more often (every 3–6 months) if eGFR is falling, ACR is high, or blood pressure is uncontrolled. Bloods also check potassium, bicarbonate, calcium, phosphate, PTH and haemoglobin once needed. Refer to a kidney specialist if eGFR < 30, ACR > 70 mg/mmol, rapid decline, or uncontrolled BP.

Can stage 3 CKD be reversed?

Stage 3 CKD cannot usually be reversed, but progression can be slowed or stopped. Tight blood pressure control (target < 130/80), an ACE inhibitor or ARB (especially if ACR raised), an SGLT2 inhibitor (dapagliflozin or empagliflozin) for proteinuric CKD or diabetes, stopping smoking, avoiding NSAIDs, and managing diabetes and cholesterol all reduce the chance of progressing to stage 4 or kidney failure.

What is the best diet for chronic kidney disease?

For most adults with CKD the strongest evidence supports a Mediterranean-style, mostly plant-based pattern with reduced salt, sensible protein, and care with phosphate additives and very high-potassium foods. Exact targets for potassium, phosphate, protein and fluid should be set by your renal team based on your eGFR and recent blood results.

Nutritional challenges in kidney disease

Many people living with kidney disease have to limit foods because of potassium, phosphate, diabetes, dialysis, appetite changes or simply the time it takes to cook from scratch every day. That can make it harder to keep daily nutrition balanced — particularly for vitamins and minerals that food alone may not fully cover.

Kidney Vitality is a UK-formulated daily nutritional support product designed by Consultant Nephrologist Professor Mohammed Mahdi Althaf with renal nutrition in mind from the start. It keeps doses moderate, leaves out added potassium, phosphate and magnesium, and avoids megadose vitamin A — sitting alongside a kidney-friendly diet, not replacing it.

Why Kidney Vitality fits this need

Built around UK guidance

Aligned with NICE NG203 (CKD), NICE TA775 (dapagliflozin), NICE TA989 (empagliflozin) and UK Kidney Association best practice.

Designed by a UK Consultant Nephrologist

Formulated and reviewed by Professor Mohammed Mahdi Althaf (GMC 7216325).

Practical, primary-care friendly

Clear monitoring, diet, BP and medication targets so you and your GP can act with confidence.

Designed by a UK Consultant Nephrologist

Ready to support your kidney health?

If you have been researching kidney health, supplements, CKD nutrition or kidney-friendly living, Kidney Vitality was developed specifically around those principles by Professor Mohammed Mahdi Althaf (GMC 7216325). Nephrologist Developed Daily Multivitamin.

  • No Added Potassium
  • No Added Magnesium
  • No Added Phosphorus
  • No Added Iron
  • One capsule daily
  • UK GMP — BRCGS, NSF GMP, Halal
Subscribe & Save — £20.39/monthCheck your current multivitamin

✓ Free UK tracked delivery  ·  ✓ Delivered every 30 days  ·  ✓ Pause or cancel anytime  ·  ✓ Never run out

ComparisonKidney VitalityTypical high-street multivitamin
Added potassiumNoneOften included
Added phosphateNoneOften included (E338–E452)
Vitamin A (retinol)No megadoseOften high-dose retinol
Kidney-focused formulationYesNo — general population
Consultant Nephrologist involvementYes (GMC 7216325)No
UK GMP manufacturedYes (BRCGS, NSF GMP)Varies

Food supplement. Not a medicine and not a treatment for kidney disease. Speak with your GP, pharmacist or renal team before starting any new supplement, especially in advanced CKD, on dialysis, post-transplant, pregnant or breastfeeding.

Clinical reviewer

Professor Mohammed Mahdi Althaf

Consultant Nephrologist

Acute Physician

GMC 7216325

View Full Biography

Professor Mohammed Mahdi Althaf is a UK Consultant Nephrologist and Acute Physician with a special interest in chronic kidney disease, AKI prevention and renal nutrition. He combines hospital practice with patient education and clinical guidance review.

View professional profile →
View Credentials
  • MD
  • MSc
  • PgDip (Clin Ed)
  • FRCP
  • FHEA
  • FASN

About this article

Written for UK patients and based on:

  • NICE guidance
  • NHS resources
  • British Dietetic Association guidance
  • Kidney Care UK resources
View methodology

Each article is researched against current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO and KDOQI international guidelines, and the British Dietetic Association Renal Nutrition Group. Drafts are written by the Kidney Vitality editorial team and reviewed by a UK Consultant Nephrologist before publication. Content is reviewed on a rolling basis and updated when guidance changes.

Editorial standards

  • Clinically reviewed
  • NHS-aligned
  • NICE-aligned
  • Evidence-based
  • Reviewed before publication
View full editorial process

Every article is researched and written by the Kidney Vitality editorial team using current UK clinical guidance (NICE NG203, NG118, NG136), NHS patient resources, KDIGO/KDOQI international guidelines, and British Dietetic Association renal nutrition guidance. Drafts are reviewed for clinical accuracy by Professor Mohammed Mahdi Althaf, MD, MSc, PgDip (Clin Ed), FRCP, FHEA, FASN (Consultant Nephrologist & Acute Physician, GMC 7216325) before publication. Content is updated when UK guidance changes.

References (4)View Sources
  1. NICE NG203: Chronic kidney disease — assessment and management
  2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD
  3. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update
  4. British Dietetic Association — Renal Nutrition Group

Medical disclaimer

This content is educational only and does not replace personalised medical advice.

Read full disclaimer

This page is general information, not personal medical advice. If you have chronic kidney disease, are on dialysis, have had a kidney transplant, are pregnant or breastfeeding, or take prescription medication, please confirm any supplement with your GP, pharmacist or renal team before starting.

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